1. Shantae (Shantae series)
2. Doom Guy (Doom series)
3. Waluigi (Mario series)
4. King K. Roon (Donkey Kong series)
5. Tetris Blocks (Tetris series)
I would also love a Female Pokemon Trainer different from Red. Maybe Mudkip, Grovyle and Blaziken would be a great combo, but it's technically a different version of an old character, so...