I don't follow or particularly enjoy Brawl, but I saw a chibi character of War from Darksiders, and had the thought of playing as him in Brawl ^^
So what Non-Nintendo characters do you think fit into the SSB gameplay and style? War is a bit easy, because of his design and similarity to Link, but I'd so throw a Predator in ^^ Combistick combo's, slow targeting, but damaging Plasmacaster, Alien tail whip for grab attacks, Smart Disc for throwing, then theres that awesome gauntlet that allows kinetic super punches.
Plus, the self distruct nuke could make a cool Final Smash. take everyone down with you.