TeamViewer - TeamViewer lets you establish a connection to any PC or server within just a few seconds.
join.me - Instant screen sharing. Instant Aha!
mRemoteNG - mRemoteNG is a fork of mRemote, an open source, tabbed, multi-protocol, remote connections manager.
Chrome Remote Desktop - The easy way to remotely connect with your home or work computer, or share your screen with others.
LogMeIn - LogMeIn gives you fast, easy remote access to your PC or Mac from your browser, desktop and mobile...
Apple Remote Desktop - Apple Remote Desktop is the best way to manage the Mac computers on your network.