After trying Skyrim and enjoying it a lot, I decided to give Oblivion a try too and play it together with Skyrim.So far I thought Oblivion's pretty good. However since there's hundreds of mods for it I'd like to know what are the must-download mods for it. Especially graphic and gameplay mods.

Also, from what I've seen Oblivion's towns suffer the same problem as Skyrim's: They're far too empty. Are there any mods that make the cities more populated?