Depends on if I ever find my pearl game or not, but considering I just realized it was lost today (even if I have looked EVERYWHERE for it), I'm still optimistic. Either way, I'm probably gonna pick Piplup, who I did pick in pearl, however, if I find pearl I'm gonna actually trade it away for an egg containing another pokémon that I feel fits as a good "starter" and go through the game as if I had picked this new pokémon at the beginning (which, really, actually matters to me, as they always stay in my party from that point on)
I haven't decided which pokémon I'm gonna use yet, I'll probably make a bunch of different eggs from ones I like, and pick one randomly.