First, I bought a wireless controller and I exchanged it for a wired--a few reasons why:
-Input lag is most noticeable if you play fighting games, which I was playing a lot of SF4 at the time.
-I use it for my PC so I normally don't sit too far away from the monitor, so the wired is fine and it eliminates me having to deal with low/no battery.
After using both, I wish I bought a wired controller first because it is much cheaper and overall more convenient, I ended up spending more money than I should buying a wireless then exchanging it for a wired, which made me want to punch a baby in the face.