So far, it's Mass Effect 2 from Bioware. But year's end is still long way to go. There are a few candidates for best RPG that should be released this year. To name a few: upcoming Alpha Protocol (Obsidian Entertainment) and The Elder Scroll 5 (Bethesda).
Although it's getting more into the direction of an action game, Mass Effect 2 is still going to be the best RPG of 2010, mainly because of the story and characters.
My favorite RPG games of all time is either Ragnarok or Diablo 2 Lord of Destruction, Because Diablo 2 was great because I had a whole gang of friends who played with me, and it's actually pretty interesting.....
No matter what, the only RPG Game i like to play is WarCraft. Outstanding man, either play on LAN or Mission . I LOVE IT. Increase you skill in huge numbers of Map and challenge anybody. I love doing map wars. ain't you all?
Bioware did a great job this year providing us with both Dragon Age and Mass Effect 2 - two really awesome RPG games. Further more, the Awakening expansion was released not so long ago for Dragon Age which is also most enjoyable.
I dont know about you but I'm playing the beta of StarCraft 2 and looks like its going to be one of the best...just saying