Both LOL.
Overall pick actually. But I'll admit I had 6 years of anticipation for that game.
For RPG of the year? I only just played a bit of Jade Empire, and honestly was disappointed that there was only one button for attacks, and it was all the same combo no matter what I guess I was expecting it to be more "action" in the action RPG
KOTOR 2 is probably the best RPG I've played this year (going back to November 2004 :D), but I think it's actually the ONLY RPG I've played this year.
EDIT: I really liked Splinter Cell: Chaos Theory though. It had excellent production values, the best story of the bunch, and finally fixed some of those annoying flaws we saw in the first two. Sam was much more badass, and the game wasn't as critical for you doing "bad" things, that wouldn't technically fail a mission IRL (just piss off superiors like Lambert).
The co-op mode is also great. My roommate and I just started playing it, and its so much fun when you're holding your breath to make sure that sentry walking past absolutely cannot hear you