Well, since sales are very important to some. look at the numbers, ps3 is speeding into 360's a$$ atm. Soon 22m.
And yes, free online,better exclusives(imho) the psn exclusives p00n, lets not forget them. Lower failure rate, im actually afraid when playing on my xbox(RROD or some error in ma face), but not on my ps3. Blu-ray,codec support,faster loading in games, cell=More sparks, more people, more physics, better AI, more particles, more of everything at the same time.(Look at kz2, lets see the box do that :) (flame me)
Now go ahead, make a list of whats better on 360. Im starting a war, lets go at it boys.
2 reasons for 360 sales.
Cheap arcade version, wich the mom buys for the kids.
And microsoft's wallet.