Not this 100 years old question. At this moment they are both very old and powerful games like BF3 works better on a new comp, with better gfx. So if you wait a year, you can get the 720
I was really confused too while buying it. But IDK why. It's really simple. 360 is cheaper, has better games, and a way better "move" in kniect. But with 360, you will have to pay for internet, and that's about $120 extra per year, which you can spend on buying games. If you already have internet, you won't have to pay separate fee. Then again, it also gets hacked like it did last year, and I just sat there for 3 months. PS3 is defo more powerful, and there are many games intended for 360, ends up working just as good on PS3. PS3 is SONY, so you can expect good quality. Apparently you can't even touch the 360 while the game is running. It scratches the disks. Also PS3 has blue ray player, which I think is a BIG BS. Like that's suppose to top them from 360. And their "move" sucks. So if you like to move around defo go with 360.
There is no wrong choice, if you pick either one, you will miss out on few good features from the other, but you won't be jeopardized. To simply put it, if you are rich go with 360, if you aren't go with PS3.