Fallout 3, to me, was kind of the biggest thing this generation because of its successful combination of RPG/FPS. I couldn't get into Oblivion, but I feel like I understand the appeal of it through my like of Fallout 3 (which, with the FPS element added, feels like a better realization of what Oblivion aimed to achieve). And as I think somebody already said above, the expansions for it just make it even better.
Other than that, I don't feel like many RPGs have especially stood out this generation. And again, I don't know if you're specific to one system.
For PS3, there's been Eternal Sonata and Demon's Souls (the latter has especially stood out). I thought Folklore was alright and fairly unique, but that hasn't gotten a lot of attention.
For Xbox 360, I'm sure some people got into Star Ocean 4, but I personally didn't. Fable 2 got good reviews. Then there's Mass Effect, and the newly released Mass Effect 2. I can't speak personally for any of these games, because I don't have a 360, but they're the titles I've noticed from across the way.