Oh boy, another one of these threads...
Ok...Well, the 360 has the best multiplayer experience of the two consoles, as well as better content delivery (from my experience). PS3 has better exclusives, I think. So really, it comes down to whatever you want. They make most games for both consoles, and they look the same on both consoles, so really the graphics and stuff have no difference.
As far as multimedia goes, the PS3 has bluray, but the 360 has better streaming video capability, so its pretty tied there as far as usefulness.