Users are reporting that TeamViewer has been compromised, leading to these users having their personal computers and browsers used in a remote session in order to purchase copious amounts of online codes.
For people that use Gmail or any other Google service, Google Hangouts is already included. No need to set up another account or manage another tool, as its already right there and integrated with Google accounts.
You can access a computer that you've previously installed LogMeIn on from any computer that has an internet connection through their browser. There is nothing to install on the computer you are accessing from.
To set up, you need to create an account on LogMeIn, download and run their software on the computer you wish to be able to access, and set the software to allow accessing that computer from the Internet.
Microsoft Remote Desktop is developed for mostly enterprise users for remote control, not to share the screen with a friend. It lacks firewall support, and is much more complicated to setup properly than some other apps, designed for fast and easy sharing.