I'll go ahead and use my second favorite game: Baldur's gate 2.

-Flesh out the party members more, give me romance options for both genders and different orientations, more quests, and give them full voice acting as the acting in the game was excellent. OH, and get rid of Nalia's worthless Thief dual-class and just make her a mage, capice?

-Balance the game some more. The game is just way too damn hard in some spots. It's part of its appeal, but I think perma-deaths should be removed entirely.

-Expand the Throne of Bhaal expansion, bringing the Bhaalspawn and stuff into more perspective.

-While alignments were somewhat important, the Lawful-Chaotic part of it was underutilized. Expand moral choice and reward players for fitting in the Law-Chaos axis into their moral decisions.

-FIX THE DAMN BUGS

Well, that was pretty much it.