If Oblivion is any indication, the PC will be the vastly superior platform... not just for technical reasons (it will look better) but for the plethora of user created mods that are likely to be made.
Also, did you just say that you like the controller better for FPS's? Blasphemy![]()
Fallout 3's mod support won't be there for a while though, Bethesda have been lukewarm on the idea of including mod tools.
I've been torn with a similar question to the OP, though I'm deciding between PS3 and PC. PC will have the extra content, but I doubt I'll ever get to it. PC will also look better, but I don't know if my 8800GT will be able to run it at 1650x1020 on high, if it can I'll be getting it on PC.
I'd say your money would be better spent on SW:Force Unleashed. But that's just me....
Ugh! Lots of heart went into that game, but it's so damn cheap!