Half-Life 2.

Kill me, burn me, rape me (hrhr...), do whatever you want to do to me, but I have to say this generation it is Final Fantasy XIII. Not only the graphics are awesome, but also the story, setting and characters are much deeper than some might assume at the beginning. Vanille, who seems to be an optimistic, always smiling girl and that seems to be in a good temper all the time, is in reality a protagonist who tries to hide her feelings of guilt by playing a fake image of herself. In my opinion, FFXIII has a lot of space for interpretations and suggestions for the players, who don't let themselves convince by some subjective opinions. I may have a different opinion to the majority of other gamers and that might have something to do with the fact, that FFXIII was actually the first FF that I played immediately at it's date of release (I have already played FFVII before, though), but I don't care. Now you can rape me.

Morrowind

Good hundreds of hours spent

Probably, Final Fantasy VI.

This gen, Mass Effect 2

Metroid Prime by far.  After that, perhaps Super Mario Galaxy 1 (the sequel was kind of rubbish).

Im going to go with Mass Effect 1 for this gen and of all time Final Fantasy X. I never played a Zelda game either or a Mario game. I Got into Games when the PS2 came out. But i did have a ps1 the only game i ever got for that console was Crash Bandicoot games. But that was when Naughty Dog was developing them and they actually were good games. 

All time: Shenmue I and II. Never played anything closer than Shenmue.

This gen: Mass Effect 2 (Never played the first game)

god of war 3 and shadow of the closuess

Peggles.

I always wanted to know what that sunflower did.

Final Fantasy VIII = Final Fantasy IX = Uncharted 2 = Metal Gear Solid 4 = God of War 3.