For me, in order of preference, it's definitely :
1) Dragon Age: Origins (+ DLCs, + Awakening)
In my book it doesn't really get any better than DAO so far.
2) Mass Effect
3) Mass Effect 2 (+ DLCs)
The original Mass Effect is the best sci-fi RPG I've ever played, period. I loved ME2 as well, but the main story arc failed flat (what made ME2 strong nonetheless was pretty much everything else, especially each individual character's own stories and loyalty missions).
4) Star Wars: Knights of the Old Republic
5) Diablo II (+ Lord of Destruction)
I've played many, many Star Wars games, from Super Star Wars on the SNES to The Force Unleashed and giving a try to The Old Republic. But the best Star Wars game to date (in my opinion) is still KOTOR (as a big RTS player I have to add, however, that I particularly liked and was very surprised by Empire at War, one of the only few good Star Wars sleeper hits out there). I know that a lot of people consider The Old Republic to be pretty much "KOTOR 3" with a different title and set online, but I disagree. A real take on an offline original KOTOR-style, Mass Effect and/or DAO-inspired KOTOR 3 would be a thousand times better.
As for ARPG, there's only a few choices (for me, anyway), and when thinking about it it always comes down (and back) to the almighty classic Diablo II (with Lord of Destruction, but DII vanilla was also superb, unfortunately I only got to play vanilla for barely one month before I decided to go buy the expansion pack since it had just been released).
And Dragon Age: Inquisition is on its way soon, it might end up being good enough to replace one of those in my above list.