Remote desktop for Mac, over internet

What's the best (easiest, and preferably free) way to control another Mac via remote desktop, over the internet?

Using Apple tools, rather than third party tools you have two options: Screen Sharing (free, inbuilt into OS X) or Apple Remote Desktop (inbuilt into OS X but admin client is paid for).

I will cover using Screen Sharing remotely across the internet. Enable the built-in Screen Sharing, as well as Remote Login, in Sharing Preferences. Allow access for the relevant users. This will work fine within the same network, however across the internet you will need to use SSH tunnelling to get Screen Sharing to work.

ssh -L 5901:localhost:5900 [email protected]

where 5901 is the local port number (up to you, best to be above 1024 though).

Then use "Connect to Server" in the Go menu of Finder and type:

vnc://localhost:5901

enter your username and password.

Other options are using Apple Remote Desktop (not very expensive from the App Store for unlimited clients, much less than "retail" from Apple), instead of Screen Sharing (which is very basic, just VNC really) and using a VPN rather than SSH tunnelling.

I'm not sure if there is anything built in or not with OSX. Logmein has a client you can install though. There are some other similar options as well (that's just the one I have used).

There also is the option of rdp (discussed here:https://superuser.com/questions/25771/free-rdp-server-for-mac-os-x)

or VNC: http://sourceforge.net/projects/osxvnc/