Gardevoir, cause it's pro.
Also!
The Latis, Misdreavus and Mismagius, Drifblim, Mantine, Gliscor, Mewtwo, Exploud, Spheal, Spoink, the Regis, the Magnemite chain (especially Jibacoil), Relicanth, Tauros, Altaria, the Three Sisters, Absol, and Haunter (but not Gengar D:<) are rather neat.
There is an even longer list available of my favorites, but I will not post it because nobody will care enough to read it.