I don't know if you game on your PC at all. If so, some of these may be irrelevant. If not, you should definitely pick them up.
Mass Effect: By far the best effort I've played this console generation. It's the closest to a cinematic experience that games have managed so far, with fully voiced dialogue (and done better than Oblivion or Fallout 3's attempts). The action is third-person shooter style, but the best part about this game is it's writing. The story is interesting and well-thought out, the characters all unique and developed. Must have this gen.
Assassin's Creed: The game has its faults (mostly in that it can get repetitive at times), but it didn't stop me from having fun. The parkour roof-running and impressively pretty graphics make this one of the most stylish games of its time. And with the sequel coming out soon (looking to correct the gaffs made in this game), it's a good time to pick up the title.
Splinter Cell: Double Agent: So this one's fairly old, but a great game nonetheless. Few are the games that do stealth anymore, and even fewer the ones that do it well. This game has a lot in replayability, as it can take several run-throughs before you figure out the best way to complete a mission. And while stealth is highly rewarded, you can still get yourself out of trouble if you mess something up. Which is nice.
Fallout 3: I've made a lot of noise about how disappointed I've been in this game. And that's true, but mostly because I'm a Fallout fangirl with impossibly perfect memories of the first two titles. Upon further reflection, I've warmed up to this game a bit. The graphics are pretty, and the first time you see the ruins of Washington is definitely a striking moment. And the story's good, if not as long as it could be (and with a very unsatisfying ending). Plenty of DLC for it, too.
And keep your eyes out for Dragon Age: Origins, which hits shelves in a few weeks and is looking to be real shiny.
