DA 2 falls so far from the tree that it disgraces the Dragon Age name. Good game, just not even close to DA:O. I will wait for many reviews and probably rent before I buy another DA game.
I prefer FO:NV to Skyrim atm. Mostly because New Vegas was fun, but the lag on Skyrim makes the game non-fun. And New Vegas was interesting, and good stories. Skyrim doesnt have any stories.
The severe bugs and leaks in FNV keep it from beating Skyrim. Honestly, I'd still be playing FNV if Skyrim weren't so bug-free, relatively speaking of course.
KotOR was a masterpiece, one of the best RPG games ever IMO. Also, why no Baldur's Gate II? Definitely a better game than the first.
I can't really compare Skyrim to all these games though, they're older and more technically limited. Skyrim's has unpolished gimmicky combat/gameplay relative to some of them, but you can't deny visually it knocks these games out of the park, as well as when it comes to size and # of hours you can sink into it.