heres my list:
1. Mario (doctor Mairo different costume), 2. Luigi, 3. Princess Peach (Daisy different costume), 4. Yoshi, 5. Bowser, 6. Wario, 7. Waluigi, 7. Diddy kong, 8. Donkey Kong, (Maybe The crock from Donkey kong as well)9. Capt. Falcon, 10. Another char from F-Zero, 11. Link (Dark Link Diff Costume, and also young Link another Costume), 12. Zelda/Shiek, 13. Ganondorf (With/ or Without Sword, diff costume for either or) 14. Fox, 15. Falco, 16. Wolff (and maybe the female wolff like fox char) 17. Kirby, 18. Meda Knight, 19. Pit, 20. baby mario and Luigi (better sounding than ice climbers, but maybe keep them too,(they could make a great team)) 21. Metroid (Zero Suit (Samus Aran), different costume) 22. Pikachu (maybe Pichu still too) 23. Mewtwo (possible mew aslo), (maybe some new ones to replace the older ones (maybe!)) 24. Marth, 25. Roy (and maybe Lynn, Elwood, Hector, Ike, to change it up... or have them as diff costumes) 26. Chrono, 27. Glenn aka Toad, 28. Magus, 29. Pit, 30. Snake( Maybe Meryl too), 32. Mr. Game and Watch, 33. Sonic, 34. Tails, 35. Knukles (and maybe EggHead, or Rouge too), 36. Ness, 37. Geeno, 38. Bowser Jr., 39. Mega Man, 40. Zero, 41. Bass, 42. Protoman, 43. Isaac, 44. Pac Man, and lastly 45. Toad (the Mario Toad this time). there that covers a lot of games and many chars... and by costumes i mean unlockable chars under same icon... Maybe instead of pressing 'Y' or 'X' to change colors you press 'Up' on the d-pad and it changes to the alternant, or if there is more than one alternant, then you would press 'down', 'left', etc... So this could be very plausible ussing this method and it wouldn't be confusing either. (I took Diomedes's idea, and thought how it could work, so i have to give him some credit for the idea in the first place ).