Recs.
Updated
Zsh is a shell designed for interactive use, although it is also a powerful scripting language.
Specs
Pros
Pro Interactive autocompletion
When you start typing a command, you can press the tab key and it will complete the command you started typing. If there are multiple potential commands, you can choose which one to run by simply pressing tab again. Case-insensitive by default, too.
Pro Great install procedure
Zsh will take you through a procedure which is roughly 30 minutes in length before during install. Through this procedure it asks you to set different options and customize the shell the way you want it to. Most of these settings are also found in other shells, but to customize them you have to go dig configuration files while zsh allows you to do it in the beginning.
Cons
Con Not fully compatible with bash
There is a small chance you may have a bash script that doesn't work in zsh, although this is very very rare and most developers will never run into any issues.
Con Requires a lot of configuration to be used fully
Zsh requires a lot of tinkering with configuration files and downloading plugins in order to be able to do tasks which other shells may be able to do out of the box.