If you are starting with a clean install of Ubuntu, what do you add to it right off the bat to add functionality or tweak it to your liking? I'm fairly new to linux so I don't have much that I would add right away and would just like to see what others add. Mainly I'm looking for things that add features or make things easier, not just programs.

So far I have found-
Nautilus-open-terminal
mountmanager
Ubuntu-Tweak