If you don't need the entire desktop on the remote machine, X-forwarding is what you want. You can connect from one X-equipped Linux/Unix/Mac/Cygwin or whatever machine to another using
ssh -X <remote hostname>
If your local machine is a windows computer you need something as cygwin (install the ssh and the X server package). On the server you don't need an X server, but you need
xbase-clients to be installed. After connecting to the server as shown above you can start any GUI application and it will be displayed on your local maschine. It is however terminated when you disconnect.
If what you are looking for is a way to run virtual machines with VirtualBox on the remote machine, then you should look into the headless mode of VirtualBox, i.e. controlling VirtualBox from the command line rather then with the GUI VirtualBox Manager.