Left4dead series: Valve is a cool developer but I tried the demo I got bored quickly. There are plenty of shooter games out and this game didn't do much differently than making everything zombies.
Bioshock: Not a bad game at all but the reviewers loved it a lot more than I did. The splicing thing wasn't much fun and some genes were obviously bad but most were balanced. The morality thing was basic and shallow. When you die you just go back to the last respawn thingy without any consequences so there really is no way to lose in this game.
Guitar hero is a great game in my opinion, I wanna play guitar but I can't yet, so until I learn it's a pretty good alternative. Once you played all the songs and perfected them to best you can it's not AS fun as at first, but still relatively enjoyable
SSBB. It's gotten so much buzz it seems like it rules other fighting games out. And Ocarina of Time. its good but I don't think it should be called the best game of all time.