360. I didn't used to have much of a preference between the PS3 and the 360, and if anything I leaned towards the PS3 whenever possible just because... I dunno, I guess because the Playstation brand has existed longer and therefore I'm more comfortable with it by default. *shrug*
The only problem for me is that I have a Bravia, and its shitty built in upscaling fumbles the ball whenever it receives anything less than a 1080p signal. It's not an issue with the 360, because it automatically upscales everything to 1080p, period, and it looks fine. But there are a ton of PS3 games that can't even be forced to 1080p, I have no choice but to run them at 720p, and they look lousy on my TV. When it comes to cross-platform relelases, I used to get the PS3 version first, hoping and praying that it would upscale to 1080p. If it wouldn't, I'd return it and get the 360 version instead. Eventually that happened so many times I finally said screw it, I'll just get the 360 version first. I'd rather deal with the getting up from the couch to swap discs once in a while than have to grit my teeth and bear inferior upscaling from start to finish.
I hope Sony can appreciate the irony of their own console displaying poorly on their own TV, compared to their rival's console... and make sure they don't pull this shit with PS4.
Speaking of 360 disc swapping-- why not do it the PC way, i.e. install all discs, then use disc 1 as the key? I assume MS is not so brain dead that they didn't think of this, what could possibly be the reason that's stopping them?