I pick "or." The reason for this is? The PC completely destroys both of these consoles in their tracks and sends them back into the factory. When it comes down to it, PCs can hold at higher resolutions, better graphics, AND can run at faster framerates with anti-aliasing far beyond what a game console can handle. Also with game consoles, you're stuck with a controller unless you wish to hack the firmware on there and get yourself something else, whereas the PC, just pop it into USB and you're all set. No USB? No problem! Just use a Serial port. Multiplayer? Awesome. PCs, unlike both of these consoles which need broadband, can do dial-up and allow you to play games over that connection.
But for the sake of the debate, I'd say PS3. While there may not be that many games, the PS3 was in fact entirely custom design, and while the Xbox 360 may have some custom parts such as a custom video card layout from ATi, the PS3 would clearly come out on top, not because of the slow Blu-Ray player, but because of performance. The PS3 has enough power to be able to run Windows Vista without a problem, and has enough power to handle Crysis with some noticable frame loss. Plus, Multiplayer is free. On the XBox, they are known to get the RRoD very common because of overheating, and you have to pay for online play which goes via XBox live, and unlike the PC or PS3 which can host games from your connection or from another server, XBox Live is technically tied to their servers, which means on busy nights, expect some lagging. There are very few games for the XBox that will use your connection to host games.
But off of the sake of the topic, the PC is the true winner. Very flexable in speed, performance, upgrades, etc despite being a bit more expensive than a console.