Peach has been my primary main in Melee for some time (I personally have yet to find anyone who I can't pulverize with her in a 1-on-1), though I typically do a continuous cycle between her, Samus, Ness, Mario, Falco (sorry!), Bowser, and the Ice Climbers -- in roughly that order. I avoid Marth and Fox as a matter of principle.
Kirby was my main back in the SSB64 days, but I stopped using him when they severely nerfed him in Melee... I'm hoping Sakurai addressed that adequately for Brawl, since I love Kirby as a character. I think I'm also going to focus on learning how to use Pit and Olimar.
Oh, and I'm new here. Hi, guys!