Right now, it's MGS4 and LBP, maybe Resistance 2 as well, and Uncharted and Ratchet and Clank.

Big ones that are yet to be released are God of War and Gran Turismo.

IMO: No game so far defines the PS3. I have discounted MGS 4 even though many PS3 owners highly rate this game because I do not like stealth games and the complex story of the MGS series is confusing. Too many cut scenes in MGS 4 is also a problem with the game. GTA IV and UnCharted are good games but do not define PS3.

Future PS3 games: FF XIII and GT 5. These games could define PS3 and push the limits of the system and be huge software sellers over 5 million copies each.

Honourable future PS3 mentions goes to Kill Zone 2 and God of War 3 both could be promising titles on PS3 which may define PS3.

In my opinion its definitely Gran Turismo, God of War, Uncharted, LBP & Resistance.

Thats the first I think off when I hear some one mention PS3 games. Personally I dont believe you can let 3rd party exclusives be the definition of console, it has to primarily consist of 1st party software that is 100% exclusive to the console.

Which is why I dont bring up MGS4 for instance.

GT5,Mgs4,God of War3

Depends on what you mean by 'define'. All those titles you mention are certainly 'killer' games for the PS3. But it's debatable whether or not they define the console. Likewise, some might disagree with the suggestion that Gears and Halo define the 360.

Twisted Metal

The awesome thing about this thread is that everyone answers different games. And it's for the reasons million mentioned.

"The ps3 isn't defined by one or two titles , it's a whole plethora of 'em.make any of most key franchises on the ps3 mutil and it's business as usual"