Treeko, not just because of his type advantage, he's better because he's really fast and that can be a really big helper in battles, I chose treeko in my Pokemon Ruby and ended up beated the eltie for with just him on level 60! No items either, exept for like two rives used in between a couple of matches.
Wazzup!!!!!! Jay-Dogg's in da house!! 50 Cent rocks. If you like 50 Cent too then join team G-Unit, and join Team Mod, because it's a great team.
G-G-G-G-G-Unit.