Mewtwo's my favorite because of his background and sheer badassness. But if we're talking non-legendaries, definitely Tyranitar. He can rape anything.
This thread already exists. A few of them I believe. But it's still Breloom. So incredibly under-rated.
Misty. That little slutty bitch was my favorite. Her special move was Lick, and it was super effective. Why the fuck can't we all just get along?
Onix we both have a fauxhawk quif thing and think about about it he's made of stone..therefore making him stoned. "This ones called mindrape, it's actually pretty mellow"