Online is tons better. I like FPSs and RPGs both of which the 360 dominates the PS3 in. The PS3 has 3 games that I liked out of my bro's 20 games. He has all the so-called big hits for the ps3 as well. The PS2 dominated last gen, but it wont this gen.
Hah, and what FPS's are those? Halo and Gears... that all? PS3 has better FPS's than the 360 than just two games. Metal Gaer Solid 4, Killzone2, Resistance, Killzone 2 , Socom Confrontation, and M.A.G that is coming out soon. Those are the big shooter games known on the PlayStation 3 real well. 360 does have more RPG's though but they don't look really great at all, but Sony is starting focus more on producing more RPG games. I've had a 360 and own a PS3, and the online isn't really a difference at all.