>>19720467Crobat has a relatively difficult evo path and sucks balls as zubat/golbat. Also his movepool is pretty shit.
Brobat is awesome but not really a great playthrough poke.
My nomination is pic related. This thing is borderline cheating. You can catch it very early in the game yet is has a base attack of 125 and a respectable 85 base speed. It also is able to learn powerful ground and rock moves to supplement its fighting. When you catch this most of your pokemon have base attack values around 80.