Is Metal Gear Solid 4 the bst ps3 game

That is debatable. I myself think that it is the best others disagree.

Pros:

Fun game play
Good story
High re-playability
Many unlockables
Many weapons
Great Graphics
A lot of Easter Eggs

Cons:

Repetitive
Game Play to cut scene ratio uneven - 75% Cut scenes 25% game play
Controls and gameplay very different from previous games