Personally I prefer PS3.
I love Ratchet and Clank, Uncharted, Resistance, Infamous, Littlebigplanet, Journey, Flower, GT5, God of War, the exclusive HD collections, and MGS4 so obviously I say PS3
If you really like Halo, Gears, Forza (basically the same as GT so I wouldn't let this be a deciding factor), and L4D (although those are on PC).
Some people say the PS3 exclusives aren't good, but I really like them and most of my collection is exclusives. Also you should take into account that Sony said they will support PS3 till at least 2015 and when you take online cost and the fact that if you buy a 4gb 360 you'll most likely have to get proprietary, overpriced, memory before too soon I actually think of it as cheaper if you do any sort of serious gaming. Also if their past systems are any indication, Sony will support PS3 even longer than that and they have a bevy of exclusives coming up next year with Puppeteer, God of War, Last of Us, Sly, and Beyond.
Another thing to take into account is PS+ which for $50 a year can keep you very entertained in dry spells (I haven't bought a new game since Sleeping Dogs and have been keeping busy on PS+ games).
I know this seemed biased but I don't buy games because of the system, I buy systems because of the games. If you have a chance try out the games I mentioned and see if you like the 360 ones more.








