PC: Lots of flexibility, you can apply skins, add sound packs. I can visit this forum whilst playing the game on the pc at the same. Without having to unplug my 360 to be able to fire the PC. Must have more sockets.
Some people have dated machines, they may find it more fun and smoother on a console.
Console: 360 Acheivement points, Xbox Live should be a good way to play online.
Cost can play a factor too if you've both a console a pc version might be cheaper.
PSP: Good old British transport, could be handy to play on that with those unexpected delays