Just played through
Donkey Kong Country : Tropical Freeze and
Punch Bowl would be the PERFECT Smash Bros. Stage.
In Tropical Freeze, Punch Bowl is an arena where you meet the next to last boss Bashmaster the Unbreakable, a giant polar bear. It's a colosseum-like structure where the penguin snowmads watch the fight and cheers on, there are waterfalls, the arena is filled with fruit-juice (filled with piranhas), there are views of the ocean and the fight takes place on a flat ice-platform that floats in the middle of the liquid.
Additions could include breakable ice-structures sent out by the bashmaster, piranhas that slowly drain life when you're in the liquid and platforms that come and go.
It's a relevant stage, a perfect representation of DK.
The music is very cool:
https://www.youtube.com/watch?v=dkxrXWokYqQ
And I just like it.
(Googled quick and found this video of the fight, low quality)
https://www.youtube.com/watch?v=NTNjWt3Rf44