If you're looking for a lightweight, fast and easy way to share your desktop with another user, then Ammyy Admin is a very good solution.
Often with screen sharing apps, there is a lengthy installation and setup process. Not so with Ammyy Admin. You don't even need to install anything - just open the .exe file and you're ready to go. The person you need to connect to also has to download and open the EXE file to be obtain the ID number.
Simply enter the ID number of the user in the Client ID field and click "Connect". The developer estimates the connection process is around 20 seconds from the moment you download Ammyy Admin to the moment of the first remote session launch.
It also claims that the program uses an advanced hybrid encryption algorithm (AES+RSA) that makes sure that connections are secure. This makes it appropriate for business dealings, connecting with clients offsite or remote connections to your office.
Finally, you can send and receive files as well as conduct voice chats meaning it's also useful for those that just want to fix a friend or relative's computer.
Ammyy Admin is a simple but powerful and effective way to make remote connections.