DrakeFox: Never used an Xbox360 controller on my PC, use a PS2->USB converter to use my old PS2's joypads.
But thought I'd chip in with this: There are PLENTY of games for the PC which support "joypads", but as it turns out the joypad needs to be an XBox360 gamepad, or you need to do some pretty nasty hacking to hope getting it working. I never got Prototype for the PC working with my joypad, it wouldn't recognize it. Super Meat boy only support the X360 controller as far as I can tell (and no keyboard remapping, for shame using the biggest and thus hardest laggiest key for twitch precision tapping, the IWTBTG sublevel 3 drove me crazy with the spacebar)
And just started playing Munch's Oddysee...or tried. The game supports gamepads, but it seems again to be Xbox only as my PS2 (which register with windows as a generic dual stick joypad) will register with the game. one button works for accept, and if I push right analog up it'll register as a cancel button press. The rest of the joypad seems to do nothing at all.
So if you plan on playing indie games with it or console ports, go with the X360 controller over other joypads. If it's for a few specific games which have been properly developed for the PC, go with what you like. If it's as a replacement for mouse/keyboard in shooters and such, stay with your mouse+keyboard.
Search up X-Padder and try it out. As far as I'm aware it'll allow you to use any gamepad for any function. You could even use it for Photoshop if you were so inclined.
I mainly use it for playing The Thing on my PC and I love it for that.