6) Bass
Rival characters are the best kind of characters, and you can never have enough of them. For example, Mega Man had Proto Man and Zero, yet he apparently needed more. So, Bass was born, as Dr. Willy’s imitation of Mega Man with probably the most hilarious and uncomfortable helmet of all time. Despite teaming up with Mega Man from time to time, Bass considers him a primary enemy. His goal is to become the strongest robot in existence, and Mega Man is obviously standing in his way of this kind of silly ambition.
Good call with Corobo. Don’t forget that he would decide willy-nilly who had to get married and have kids.
No Pokey from EarthBound? :(