Fighting games are best played with 8-Way D-Pads (Especially 2D fighters or a 2D/3D mix like this). It isn't as bad with something like Tekken that mostly involves pushing the direction and attack and not the rolling movements you need with 2D fighters. The Sony controllers are 4-Way pads and the 360 D-Pad is just complete shit. The Sony controllers are pretty much 110% shit though so at least the 360 controller is only bad for fighting. The triggers are awful for racing games, the sticks are too loose for shooters and the list can go on and on about the flaws of the Sony controller. And don't even get me started on the PSP's nub
It really is a mess of a controller and yet here we are after three consoles using the exact same piece of shit. And no even if for whatever reason you do like the Sony controller for a fighting game there is not a PC controller that wouldn't be better since there are improved versions of the Sony controllers. Or if you like the pathetically bad D-Pad on the 360 controller you can use that with a PC without even needing to buy another controller.
P990 Dual Analog Pad
But something like that is what one should really buy if they get this for PC.
But obviously if people don't have a gaming PC the PS3 controller is at least better than the 360 D-Pad. XBLA fighting games have been slammed in reviews and by gamers simply because the controller is making them so unplayable.