GNOME vs KDE Plasma
When comparing GNOME vs KDE Plasma, the Slant community recommends GNOME for most people. In the question“What are the best Linux desktop environments with high DPI support for retina displays?” GNOME is ranked 1st while KDE Plasma is ranked 2nd. The most important reason people chose GNOME is:
Every aspect of GNOME has been crafted to fit together as a harmonious whole, so that it offers a consistent and integrated experience.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Clean UI
Every aspect of GNOME has been crafted to fit together as a harmonious whole, so that it offers a consistent and integrated experience.
Pro Online account management
GNOME integrates with your online accounts, so that all your data can be accessed from the same place.

Pro Wayland support
Gnome is the first desktop environment that uses Wayland as default instead of X server. X server is only optional currently.

Pro Keyboard friendly
It's (mostly) usable without touching a mouse, so you can keep your hands on the keyboard.
Shortcuts can be defined in the gnome setting.
There are even more shortcuts available when using the gesetting or dconf tool, e.g. switch to desktop 5 to 9.
Pro Highly stable
Gnome isn't obviously devoid of flaws, but it's pretty stable - especially in comparison with the KDE Plasma Desktop, which can literally fall apart after installing upgrades (and show a considerable number of error messages) or for whatever reasons - after turning on the computer you can end up without (Plasma) desktop altogether, which is quite unproductive. It is also noteworthy that many other major desktop environments are based on Gnome, and among these are: Cinnamon, Pantheon and (now dead) Unity.

Pro Great for high dpi displays
Adjustable scaling factor makes it great for high-resolution laptops and far away TVs.
Pro It just works
You don't ever "need" tweaks. Unless your device is too outdated, it just works out of the box. Touchscreen, 4k TV, anything just works.
Pro Simple and easy to use
GNOME has been designed to make it simple and easy to use. Press a button to view your open windows, launch applications or check if you have new messages.
Pro Powerful search
A powerful search feature lets you access all your work from one place.
Pro Does not get in the way
GNOME lets you do the things you want without getting in the way. It won't bother you or badger you with demands, and it has been designed to help you comfortably deal with notifications.
Pro Very productive
With a clean layout and well-thought keyboard shortcuts, Gnome is simply the best for people looking to be productive with their computer.

Pro Easy theming
Changing the look (and feel) of Gnome Shell is easy, shell theme, icon, windows and graphical elements (gtk) individually for each user.
Mostly it's installing some packages or unpacking some archive to a themes folder and using selecting the new theme in e.g. gnome-tweak-tool.
There are a lot of really good themes on DeviantArt.
Pro Gnome-Tweak-Tool is great
Gnome may seem bland out of the box but, the Gnome-Tweak-Tool is awesome.
The Gnome-Tweak-Tool allows for easy desktop tweaks and other control functionality, and that these features can be activated with just a click.
Pro Adheres to standards
Allowing for interoperability and shared technology for X Window System desktops.

Pro Highly customisable
Gnome Extensions offers an easy way to extend the built-in functionality.
Pro Touchscreen friendly
It works well with any touchscreen-enabled system, including newer laptops, even to the point of including a well-designed on-screen keyboard.
Pro Beautiful interface
Very, very beautiful interface.

Pro Great task manager
The GNOME Task Manager is great, showing all open processes with every needed detail. For each process you can see the amount of memory and processing power that it's using, along with the process priority.
Pro Graphic apps 'feel smoother' on gnome than on KDE plasma
Graphics apps 'feel smoother' on gnome than on KDE plasma. Example: Gimp and inkscape, probably because they are developed in gtk+.
Pro Integrates with most Google Services
You can use your calendar, drive, contacts and most of Google services with Online Account option. You can show your Google Calendar events on the Gnome's default calendar app, Nautilus (Default file manager of GNOME) almost fully integrated with Google Drive and even you can read your PDF's with Evince (the default built-in PDF reader in GNOME).
Pro Effective default workflow
Gnome is not very tweakable but its defaults are sane enough that you it is very usable out of the box. Especially if you like a keyboard driven workflow and an uncluttered interface. The lack of options and features makes it a distraction free and clean UI to focus on what matters.
Pro Great for minimalists
It may only do several things, but it's very good at each one of those things. You won't get lost in customization menus, and you certainly won't have an stability issues as long as your hardware is made within the last 10 years.
Pro High resolution screens, multi monitor, content creation
If you depend on high resolution screens, multi monitor, or content creation programs you want Gnome.
Pro All the major players in the Linux ecosystem have finally collated on Gnome
Red Hat default = Gnome
Fedora default = Gnome
Debian default = Gnome
Ubuntu default = Gnome
Opensuse default = Gnome
This doesn't mean the others go away, it just means there is a colossal community and industry backing behind Gnome.
The point whether or not it being technically the best option is now off table and irrelevant. It is now the de facto standard. Like it or not.
Pro Hamburger Menus
If you use a Mouse you fell like a second class user.
Pro Tons of extensions at extensions.gnome.org
You can add infinite customizations with extensions
Pro Original idea
It's not another desktop experience based on "windows experience" . It's original. The creativity of developers is great.
Pro Extensive
Can be customized by lots of add-ons and themes for gnome-shell.
Pro Reall the only original and complete Desktop Environment
The Gnome-Shell paradigm is wildly different from Windows, and isn't all that much like OSX either - it's a different workflow that, if it appeals to you, is a dream to use. Every other DE is either like Windows, like OSX, or like OpenBox.
Pro Now lighter than xfce
Gnome by default is slow. But after some tweaks, gnome becomes lightweight and also much faster than xfce. It is also more user-friendly.
Pro Has a file manager that provides a good balance between power and simplicity
Included file manager provides several icon, list and detail views to choose from along with features such as tabs, bookmarks, tagging, previews and metadata, network file access, bluetooth file transfers to/from devices and excellent removable storage integration while remaining fast and easy to use.
Pro Highly flexible
There are many customization options and possibilities to tweak the desktop, including widgets.
Pro Looks beautiful
The design of the three built-in desktop themes; Air, Breeze, and Oxygen, are very beautiful to some.
Pro Adheres to standards
Standards adherence allows for interoperability and shared technology for X Window System desktops, with similar Wayland support being worked on. Applications not written with Plasma in mind work very well in Plasma as a result. The development team has also been instrumental in standard creation and adoption such as NETWM, X11 clipboard, icon themes, mimetype handling, application menu standardization, system tray protocols and notifications and more.
Pro Keyboard friendly
Nearly all actions can be driven with keyboard commands. Window management, including effects such as desktop overviews, can be triggered with a keyboard control (or mouse gesture) and some even support filtering results (such as windows shown) by typing. The KRunner tool (default keybinding: Alt+F2 or Alt+Space) provides searching local files, online sources, unit conversions, math and more all from a keyboard driven interface.
Pro Comes with a suite of powerful applications
Plasma Desktop generally comes packaged with a full set of applications to get users started, including a file manager (Dolphin), advanced file manager and browser (Konqueror), image and document viewers (Gwenview, Okular), the Calligra office suite, CD and DVD authoring (K3b) and dozens more. The desktop can be installed and used without these applications, but they add significant value for many people.
Pro Integrated advanced search
Plasma Desktop comes with an integration search system that makes it easy to find local files, emails, contacts, events and more. The file manager supports tagging and rating files as well as full-content searching and the KRunner command window and the Milou desktop widget makes searching for files, emails, applications and other content by name, subject, category, tag, fulltext, etc. very simple. It does this with essentially no noticeable interference with day-to-day usage of the computer, thanks to the scheduling built into the backend system (Baloo).
Pro Multi-device "convergence"
Plasma Desktop provides seamless "zero config" integration of your Android device with your laptop and desktop machines via KDE Connect. Phone calls, SMS messages, cross-device copy and paste, media remote control, cursor control and more are supported.
The technology that Plasma Desktop is built on, simply called "Plasma", also provides interfaces for phones, tablets, netbooks, and media centers in addition to the desktop. These additional interfaces use the same underlying frameworks and therefore work well together and have a unified feel to them. They also support a common set of applications across them which adapt to the input methods and screen sizes.
Pro Great HiDPI support
Scales well with laptop and big home theater screen simultaneously.
Pro Bunch of coherent applications
What make plasma so nice is the galaxy of apps, sharing same look and feel, configuration and behaviour.
Pro KDE is an evolution on the classic desktop model
KDE 4 is a great evolution on the classic Win95/Gnome/XFCE approach. It's moving in innovative directions while respecting the classic metaphors.
Cons
Con Longtime support is hard since every few years GNOME changes its own standards
Everytime something is complete GNOME breaks itself:
Icon naming changes almost every 3 years : once gtk icons were named stock_edit then gtk-edit then edit-edit and currently edit-edit-symbolic
- App icons change also every few years currently they get renamed to an android like scheme eg: org.gnome.Photos.svg instead of gnome-photos.svg however this breaks all common standards esp. since filenames on linux are case sensitive.
GNOMEShell extension also break on almost every release.
Currently Gtk3 has been stabilized however they are already working on GTK4 and 5 so in the worst case your desktop will need to run and support 4 GTK-toolkits at the same time.
Con Slow
GNOME desktop environment is kinda slow on some Linux distributions.
Con Full screen start menu
This may be fine if your screen is really small, but on modern fullHD desktop it looks ugly and distracting. In addition to very ineffective display of items on screen - much more could be placed on one screen if there were less empty space around and between icons.
Con Extensions can break whole Gnome desktop
Gnome extensions have a lot of freedom to customize the desktop, and it means that extensions can break your desktop leaving you unable to use your computer. Also extensions can significantly slow down whole desktop.
Con Continuous customization and extension issues
They need to sort out their continuous customization and extension issues, which are why many people still prefer KDE or other Desktop environments.
Con Poor 'drag and drop into application' capability
Difficult to drag and drop a file into an open application.
Con Some settings are not where the user would expect it
E.g. it is not possible to change the keyboard auto-repeat delay or rate from the usual All Setting > Keyboard like, for example, in Unity.
Many settings are considered "tweaks" and require installing a separate utility to adjust.
Further still, some settings are buried in a dconf database.
Con Some GUI controls are much larger than on other desktops
This is wasting screen space on non-HiDPI monitors.
Con Default alt-tab behaviour is cute but extremely annoying for fast keyboard users
Con Native Gnome dock isn't scalable
The native Gnome dock isn't scalable, which means if you want to change its size you have to download a customized theme for the shell and hope it has the appearance you want. Honestly again just like the icon issue it wastes way too much of the screen on high resolution monitors.
Con Tightly coupled to its window manager
If you're looking to run an alternative window manager, like XMonad, you're pretty much out of luck.
Con Not truly tunable
Customization is very limited.
Con Removes more features than it adds

Con Extension system is weakly integrated into the environment
Backward compatibility is not guaranteed and extensions seems like second class citizens in the GNOME environment.
Con You can't put icons on the desktop
You have to enable the ability to add icons and files onto the desktop with Tweaks that you have to install.
Con You can't put icons on the desktop
Con Rather insane method of wallpaper slideshows
Most DEs and WMs allow the user to simply point to a directory, and use pictures from there. Gnome 3 requires the rather asinine idea of building an XML file to accomplish the same thing.
Con No support for fractional scaling
Unlike Qt, GTK has no support for it.
Con Depends too much on extensions to customize basic settings
Con Depends on systemd
Some people don't like systemd but it is part of most modern distros anyway.
Con Has several dead userspace features that are supplemented by community supported extensions
Has several dead projects that are supplemented by community supported extensions. Unfortunately, the gnome updates often break these extensions. Example: GSConnect.
Con Heavy-weight, PC unfriendly desktop
Heavy-weight on disk space, on package number, on dependencies, on CPU resources, on RAM, on GPU, with a style better tailored to mobiles.
Con Sacrifices usability for one style
There's one style (adwaita) and that's the one supported style.
Con Bloated and energy-intensive
Con Made for touchscreens
It's very uncomfortable to use with a mouse and a keyboard.
Con Icon scalability and sorting
The icons in the "apps view" area don't have any additional sizes, the current ones are much too large to be effective for the screen space they use. Also, there is no native way to sort them in Gnome, only a very limited extension. Which means you're pretty much always better off using the search bar if you can.
Con Deprecated
Is replaced by Gnome 40.
Con Out of Date
Gnome 3 is out of date now that Gnome 40 exists. It's still great, but the new version's switch to GTK4 and improved (IMHO) UX make 3 feel obsolete.
Con Inconsistent desktop
As of GNOME3, some applications have ClientSideDecorations while other use normal Titlebars, this also affects usablity since both Decorations do different things if you left, right, or double click it. Same goes for Menubars. Some Apps follow the GlobalMenu in the GNOMEShell while others don't.
Con Shell-Style ≠ Widget-Style
The GNOME-shell is unable to use the current GTK style for its interface thus making it hard to get a consistent user interface.

Con Non-intuitive use paradigm
It doesn't feature an always-on dock and fixed amount of usable desktops, doesn't support tray icons for background programs. The main interaction with running programs bases on clicking and dragging (to a desktop) preview thumbnails.
Con Stability problems
Under certain conditions, most of KDE's components can be highly sensitive to race conditions, which leads to KDE applications frequently crashing, and, on rare occasion, kdeinit itself locking up.
Con Perceived clunkyness and slowness
Compared to other options, KDE is still perceived slow. Especially, the desktop takes a few seconds to login.
Mouse pointer can feel sluggish, or laggy, on older systems.
Con HiDPI support is great
One can even synchronize the login screen to scale with the rest of the DE
