From a hardware stand point, PS3 is better.
If you compare 360's launch titles vs. PS3 launch, you can tell.
PS3 has the cell (4 times faster than a quad-core but not the fastest processor in the world; impressive none-the-less.)
Xbox 360 has a slightly better GPU compared to the PS3's RSX.
BUT, the PS3's CPU -the cell- is enormously more powerful than the 360's Xenon.
If the developers are talented, they can use the CPU and GPU of the PS3 as one, with incredible results.
PS3 has 7 'cores', 1 reserved for the architecture while the 360 has 3, 1 reserved for the system.
Most games out right now only use a few and not all the cores.
Of course, everyone has their biases and I've seen a bunch of Xbots in real life and they haven't got a clue about the PS3.
So the physics, graphics, sound of the PS3 will make the 360 a run for their money in a few years when the noobs learn how to master the PS3.
PSN is FREE dedicated server.
Xbox is paid p2p (lol?)
I can go on and on but you probably think I'm lying and hate me.