Stages that need to happen:
Crateria from Super Metroid: the starting area with the ship and the rain, iconic location and has an aesthetic we have yet to see(I just want a stage with visual rain, **** distant planet)
Dragon's Gate from FE7: probably the single most iconic location from the series, has an unique color palette too. Let Hector bring it with him.
Tal Tal Heights from Link's Awakening: my favorite Zelda game needs more love, it only has one song and it's a remix of this area's theme. Just... god, please give me it. It'd be a beautiful mountain scenery with the Wind Fish Egg in the background and it'd give us am excuse to get Marin's Song.
Airship from FF??: Airships are such an iconic part of the series and I'd love to see one represented. While I'd love it to be based off FFVI, I think basing it on FFIV would be the best as it could travel from the overworld, to the underground and all the way into the space and the moon.
****ing Mt. Silver: how the hell isn't this in yet??? ****ing anti-gen 2 bias. As you can see from my list, I like stage concepts mainly for their Aesthetic™ and this one takes the cake with a full on blizzard that'd take place all throughout the battle and as a reference to the games, it'd damage all fighters(except the Ice Climbers) throughout the match.