Fact: More people are of the opinion that in total, the 360 has more games that deserve a higher score then the PS3 has with its game. As evidenced by Metacritic and Gamerankings.
That leads to the assumption that: The 360 has a better games library then the PS3's.
Personally, I think it does. It has good/great games in almost every genre, meaning that no matter what I like to play, there's always something there for me. PS3's library can't necessarily do that. Also, of the best titles i.e AAA, the 360 over the last few years (so basically last 2) have had a much more steady release of these titles, whereas PS3 hasn't seen that yet (it will see it these holidays, but beyond that? who knows).
Also, I think OP's username suits him or her very well, because one game doesn't make a console successful, look at Halo and the xbox.
Right now that's what the PS3 is doing, with MGS4 the lone truly outstanding exclusive title in the library (R1, Uncharted and R&C are all great titles, but they aren't up there with the likes of MGS4, Bioshock, Mass Effect, Halo 3, Gears).
Again, That'll change, but as it stands 360 library >>>>>> PS3 library.
NOTE: This is all my opinion and if you don't agree with it, that's your opinion.