Honestly, I tired of Skyrim after not being told by the game that it'll just randomly save OVER my other saves with it's auto-save when I tried toi play a new game with a different class, race, etc.
What I have gotten back into in the past few days is Red Dead Redemption. I've had long enough of a break to really get it out of my system, so when I hopped back into the multiplayer yesterday and today it really hit me hard just how damn good this game still is.
So yeah, I'm voting for Red Dead Redemption. An amazing story which will take you about a week to blaze through (depending on how much you play the game) and a multiplayer that is honestly unlike any other on the market.
Runner-up prize goes to Mass Effect 2. It'll last you a damn sight longer than RDR if you take every side mission you can, but I just don't love it as much as some good old fashioned cowboys and indians action.