A few characters I would've loved to see in Brawl, and wouldn't mind being included in the next Smash Bros:
-Midna (imp-Midna, barbie-Midna, wolf riding-Midna, they're all good. just give us Midna!)
-Ridley (in b4 shitstorm. yes, I think he could be shrunk to a workable size)
-Ganondorf with his sword (a heavyweight swordsman would be very interesting to play)