Oblivion is amazing from many technical aspects, but suffers from many bad design decisions (map design, leveling system) and a large sense of generic-ness.
Here's a couple of *examples* of what the community has done to improve the game.
FCOM (in beta)
http://www.youtube.com/watch?v=Pd6G9zK4D5A
Deadly Combat (v4 works good, v5 in testing)
http://www.youtube.com/watch?v=AdPt0En3ovg
Midas Mighty Magic
http://www.youtube.com/watch?v=LL2sr7RXdEc
And not to mention character creation and races
http://s203.photobucket.com/albums/aa261/deathknowz/?action=view¤t=cb736861.pbw
I got about 75+ mods installed in Oblivion currently. :)
Btw, just for my own scale. ;)
Modded Oblivion >>>>>>>>>Modded Morrowind>>>Morrowind>>>>>>Oblivion
Nobody is crazy enough to accuse me of being sane.







