I never played the handheld Metroid games, so I can't speak for those, but I do know that Ridley was in every console Metroid game (don't know about Prime 2, didn't play that either) since day 1. Now granted, he was just one of 3 boss characters in the original, by the time we got to the third installment (Super Metroid on SNES) he was like the second in command for the space pirates and a major character in the game (not just one of the bosses, but part of the main story). Meanwhile, Dark Samus would be a terrible contribution to Brawl, cuz he/she would just be a clone of Samus, what a waste of space, should just be a different costume of Samus. How dare you say Dark Samus is a better representation of Metroid than Ridley, shame on yourself. Ridley has earned his right to be in Brawl, Dark Samus was just a gimmick character designed to go with the dark/light design of Prime 2.