No, the PS3 is a mediocre Blu-ray player at best, I have owned 8 different players, including a PS3 and the first gen stand alones bested it in my tests (same disk, same cables etc)
It is a great gaming system, and can become addicting, but it should not be confused with a good Blu-ray player.
Case in point, I bought a Sony BDP-S350 the other day and it is better than the PS3 in picture, and loads amazingly fast and is cheaper!