New Vegas is great. I think it's a real step up from Fallout 3. The new weapons, minigames such as gambling or the new collectible card game Caravan, and the setting..I really just enjoyed all of it. You can sink a lot of time into that game.
As for Folklore, I can't really say. I doubt I even got an hour into it. Another CAG posted a review of it in the blogs section a few weeks ago, or a month ago, or something like that. I'd check it out.