In black, i mostly had either mienshao or hydreigon as leader.
in black 2, its either whoever im trying to level, or its N's Zoroark. He's that kickass. Though, when i get to it, i might make Metagross the leader, cause its so AWESOME.
After the e4, if i can get one, im replacing my arcanine with a dw blaziken, since a torchic was my first ever pokemon. (Anyone know where i can find a shop with an adamant dw blaziken in stock? Just pm me the answer.)