What (characters, arenas, etc) would you like to see in a future SSB?
This is what I am suggesting. I don't expect everything (I list here) to be in a future Super Smash Bros game. These are just ideas.
Super Mario
*Characters: Mario, Luigi, Peach, Waluigi, Bowser and Bowser Jr
*Assist Trophies: Lakitu, Hammer Bros, Mole-in-Tank (New Super Mario Bros), Birdo and/or Boo
*Arenas: Warship (Super Mario Bros 3), Bowser's Castle (either from Super Mario Bros 3, Super Mario World or New Super Mario Bros), Subcon Kingdom (world 7 from Super Mario Bros 2) Mushroom Kingdom (from New Super Mario Bros), Battle Arena 2 (Super Mario Kart), Mushroom City (Mario Kart Double Dash) and/or Princess Peach's Castle
*Music Tracks: Final Battle (original-New Super Mario Bros), Koopaling Boss Battle (Super Mario World), World 8 (original- Super Mario Bros 3), Main Theme (New Super Mario Bros), Battle Mode (Super Mario Kart- Mario Kart Wii version), Special Zone (Super Mario World) and/or Princess Peach's Castle (Melee)
Donkey Kong
*Characters: Donkey Kong, Diddy Kong, Dixie Kong and King K. Rool
*Assist Trophies: Rambi Rhino, Funky Kong, Kiddy Kong, Klap Trap, Krusha and/or birds (from level 4 of Classic NES Donkey Kong Jr)
*Arenas: Level 1 or Level 2 (Donkey Kong Jr), Gangplank Galleon, Krazy Kremland (theme park from Donkey Kong Country 2), Kastle Kaos (from Donkey Kong Country 3), Oil Drum Alley (from Donkey Kong Country) and/or Level 3 (Donkey Kong)
*Music Tracks: Main Theme (original-Donkey Kong Jr), Main Theme (original-Donkey Kong), Stilt Village (Donkey Kong Country 3), Arich Boss (original-Donkey Kong Country 3), Crocodile Cacophony (Donkey Kong Country 2), Disco Train (original-Donkey Kong Country 2), Snakey Shanty (Donkey Kong Country 2) and/or Temple (Donkey Kong Country)
The Legend of Zelda
*Characters: Link, Zelda/Sheik, Ganondorf, Zant and Toon Link
*Assist Trophies: Shadow Beast, Rusl, Vaati, Darbus, Skull Kid with Majora's Mask, The Three Goddesses (Farore, Din and Nayru) and/or Impa
*Arenas: Pyramid of Power (A Link to the Past), Hyrule Castle (Ocarina of Time or Twilight Princess), Ganon's Castle (Ocarina of Time), Mirror Chamber, Great Bay, The Great Temple (The Adventure of Link), The Bridge of Eldin, Outset Island and/or City in the Sky
*Music Tracks: Hidden Mountain and Forest (Brawl version), Termina Field, Main Theme (Link's Awakening), City in the Sky (original-Twilight Princess), Zant battle (original-Twilight Princess), Great Temple/Temple, Midna's Lament, Molgera Battle, Ganondorf battle (Ocarina of Time), Gerudo pirates Theme (original-Majora's Mask) and/or Ganon's Dungeon (The Legend of Zelda-Tetris DS version)
Metroid
*Character: Samus (original suit and Fusion suit)
*Assist Trophies: X Parasite, Metroid and/or Space Pirate
*Arenas: Main Deck, Sector 1, Sector 4 or Sector 6 (Metroid Fusion), Norfair, Frigate Orpheon, Brinstar Depths and/or Chozodia (Metroid Zero Mission)
*Music Tracks: Sector 1, Sector 4 (upper), Sector 4 (lower), Sector 6, Norfair (Metroid Zero Mission), Kraid battle (original-Metroid Zero Mission), Space Pirate Mother Ship (original-Metroid Zero Mission) and/or vs Ridley
Killer Instinct
*Characters: Jago, Fulgore and/or Spinal
*Assist Trophies: Spinal (if he isn't a playable character), Cinder, Orchid, Riptor and/or Glacius
*Arenas: City Rooftop (Orchid's arena in KI1), Tiger Temple (Jago's arena in KI1), Desert Rooftop (Cinder's arena in KI1), Castle Rooftop (Spinal's arena in KI1) and/or The Factory (Fulgore's arena in KI1)
*Music Tracks: Fulgore's theme (original-Killer Instinct), Orchid's Theme (Killer Instinct), Riptor's theme, Jago's theme (original-Killer Instinct), Cinder's theme and/or character select (original-Killer Instinct)
More to come