StingingVelvet: Wireless 360 controllers have some issues with certain games, and they cost a lot more. I'm sure someone will comment "I haven't had any problems" but I read about them on the Steam forums all the time. Usually it's the analog triggers not working, I think one of the Assassin's Creed games had this issue.
I would personally suggest a wired version, which is what I use. I got mine for cheap, only $20 on amazon. If you're at a computer desk it really doesn't matter anyway. If you're using your PC in a living room setting though, then obviously your situation is different from mine.
I have a wireless 360 and I've had excactly those problems. Therefore, in hindsight, I would also get the wired version (unless you have a beamer and a couch)
But generally I'm very happy with my pad. It is also a good pad if you have big hands and also very sturdy (as SF IV has shown me). You
will have a lot of problems with older games, due to a driver issue, so that is always to keep in mind. But if you are looking for a gamepad for modern games, this is the one for you.