If Sonic's ever going to be in Brawl, then I think the Doom Marine should be in there too. Seriously! I mean, he'd have a pretty low jump height, but compensate with his firepower. Maybe one of his specials would be the BFG...oh, dang, that would rock. And Microsoft has gone on the record as saying they respect Nintendo a great deal, so Master Chief would be great too, especially if he uses plasma grenades and maybe the Warthog...