I always do this with a level list. I start it, get further down it, and realize I don't know anything about other games. So here is my list, as well as how I think the levels should be distributed.
Super Mario (With Yoshi and Wario!)
• Peach’s Castle
• NSMB/Mushroom Kingdom “III” type level
• Luigi’s Mansion Level
• Galaxy Based level
• *random level from Sunshine, or Bower’s Airship/Castle, WHATEVER*
• Yoshi level
• WarioWare level (Doubt we will ever get much LAND content)
Mario (5) Yoshi (1) Wario (1)
Donkey Kong
• Donkey Kong Country Returns Based level
• *random past or new level based off of any DK game*
DK (2)
Kirby
• Green Greens
• Epic Yarn level
• *random level, like FoD or Halberd*
Kirby (3)
Legend Of Zelda
• Temple
• SS based level
• OoT3D based level
• *random level like MM3D based, or a new Zelda based level*
LoZ (4)
Pokemon
• Pokemon Stadium
• Black and White Based level
• *random level based on any of the newish PKMN games (Park, HGSS, RS3D?, ect)
Pokemon (3)
Metroid
• Something with lava or burny stuff
• Other M based level
Metroid (2)
F-Zero (1-2)
Mother (1-2)
StarFox (2) (Big ship based level AND a new level)
Fire Emblem (1-2)
Pikmin (1)
G&W (1)
Ice Climbers (1)
Kid Icarus (1-2)
Ninty Hardware (2-3) (Pictochat, Mii Plaza, bunch of crap to base it off of)
Punch Out!! (1)
Animal Crossing (1)
Golden Sun (1)
Endless Ocean (1)
Sin & Punishment (1)
Xenoblade (1)
Tetris/Puzzle League (1)
The Last Story (1)
Balloon Fight (1)
Sports Resort (1)
Custom Robo (1)
Legendary Starfy (1)
New Retro character level (1)
Zombie mode? Interesting...
I suggested this forever ago as a part of my Jill Valentine stuff. A level based on SURVIVING. Zombies come out at night, ect. Also made a Jill moveset, bosses, colors, AT, and Trophies.