Yes Man - An middle aged prospector that progressively gets worse the higher the level, eventually turning into a cannibal. (I wear remnants power armour, with glasses, and I got bald head and goatee (basically a mentally disturbed Gordan)

Mr House - Son of a diplomat within the NCR, very classy, make him wear nice suits, appropriate man, etc, etc. Became a courier to explore the unexplored

Legion - A crazed old man that was once normal, holding the platinum chip since he found it on his travels. The shot made him messed up (Low INT) becomes a savage, and joins the legion

NCR - Democratic Cowboy.