If you get an adapter to use a 360 controller on a PS3 (they exist, kinda expensive though), then PS3.
Otherwise i'd get a 360 since most titles are on both anyway, and PS3 exclusives aren't really that fun, except Valkyria Chronicles...which by itself justifies purchasing a PS3.
If I had bought my PS3, beat Valkyria Chronicles, and then my PS3 exploded right after...i'd have been completely satisfied with it.
There's a few exclusive jRPGs on the PS3 that are also worth mentioning, like Tales of Graces F in march, or the better version of Eternal Sonata. It REALLY depends on what games you like though, asking the internet "which is better" is retarded, because everyone has preferences towards the console with more games they like, or which console delivers that game better (360 for online, PS3 for tending to have "better" versions of RPGs from 360).
PS3 controller is fine for slow-paced games like puzzles and turn based RPGs, but anything action or FPS is just ruined by it. Don't believe me? Play NInja Gaiden on both consoles. Best example ever. I nearly broke my disk in half when I bought and played Ninja Gaiden for my PS3. There's a difference between "preference" and "outdated and poor build quality".