I've seen a few people ask about Witcher 2 remasters/remakes, but I honestly think it looks as good/better than half the games released today!The Witcher 1, maybe even spruce up The Witcher 2 a bit as well (even though it looks great already!).
Someone mentioned Morrowind earlier; good choice, but community mods do it a better service than what Bethesda could come up with. On a similar note though, I'd like their future games to have the same amount of depth / complexity / challenge.
Also, Mercenaries and Destroy All Humans! 2. The remake of the first game was solid, so it would be cool to see some of Pandemic's other titles see the light of day again.