Hmmm...tough one. Either Hitmontop, Gallade or Poliwrath. Here's my reasons:
Hitmontop - 2 great abilities, decent defence and attack, and a monstrous special defense helps it to survive longer than most.
Poliwrath - 2 great abilities (Water Absorb is superior to Damp, however), unique typing, it's a Poli, it looks cool, its' average, but not poor stats allow it fulfil a variety of roles. Oh, and Red has one.
Gallade - Looks cool, part of the Ralts family, better special defense, and attack, than Hitmontop, but less defense. It's overall pretty awesome.