GTA 4 your own personal choice i personaly think its a good game and love the free roam and online game types.

COD4 is a different matter , not only is cod4 the most modern game of it type it is also the very best game of its type but with the new call of duty 5 world at war launching on the 11th of november im wondering if there would be any point in getting COD4.

also saints row 2 is coming out on the 4th of october and i heard that they may be making the game for the PS3 unlike the the first saints row.

i have a xbox 360 and love the games and alot of games are coming out on the PS3 that were only ment to be for the xbox 360, the list below is a big list of lots of games that i think are good and game that arent out yet but you should keep and eye on but im not 100% sure if they are all on the PS3.

fifa 09 - not out ( not sure on realease date )
pes 09 - not out ( not sure on release date )
cod4 - out
cod5 - out on 11th of november
mercanaries 2 - out
saints row 2 - october 14th
fable 2 - not out ( not sure on release date )
gta4 - out
bejing 08 - out ( but very hard game )
civilization revolution - out ( the best strategy game ever ! )
guitar hero 3 - out ( very good and fun game )
halo 3 - out ( good game worth the buy )
oblivion - out ( best role playing game )