That changes all the time with new releases ans increased popularity of different games. Gamespot has a list on the related link for most popular and also highest rated.
There is no best, it's all based on opinion. I personally though like MGS4 and COD:MW2
resistance fall of man. it was the only FPS out when the ps3 released
NO it was aclaimed the BEST PS3 game!
the best ps3 game is What ever you think
Infamous 2
Ps3 or psp are the best.
In my opinion Dead Island is the best, it depends on what you think of the game.
FALLOUT 3
uncharted 2
Demon's Souls
Killzone 3
fifa 11