Should I buy a ps3 or stick with the 360?

I currently own a xbox 360 the only problem is I have no xbox live because of where I live and most of the games replay value is online. I love m effect, halo 3, and gears of war 2, but I don't know how much I would like the ps3 because I have never tried it. I plan to keep my xbox 360 but is it worth buyig a ps3 for the games. I like singleplayer games, roleplaying and shooter mostly. Also if I ever go to my friends place who has wifi I can play online for free, I can't with live because I havnt paid for it since most of the time i don't have it. Also my xbox is from 2006 and is vetting old and hard to read games and movies. Thanks