DragonFreak
Everything that drowns me makes me wanna fly!
I've only played Brawl, but here are my top 5 favorite and least favorite stages.
Favorite:
Luigi's Mansion - I love how you can destroy the mansion, and it'll rebuild after being destroyed.
Mushroomy Kingdom - This stage actually acts as two stages, one aboveground and underground. And items that appear are numerous and gets very chaotic, which I love Chaos.
Pokemon Stadium 2 - The constantly change of this stage is awesome. It creates very interesting battle strategies.
WarioWare - Love it for the minigames and nothing else.
The retro Yoshi's Island - I love it because it looks like Super Mario World.
Least Favorite:
Flat Zone 2 - It's awkward and too small for my liking.
Spear Pillar - The stage KOs me more than anything, and some of the special events, like when things get upside-down or the controls being opposite are super annoying.
75m - Love the design, but hate to play it. There's not enough platforms to make it interesting enough.
Hanenbow - not enough platforms, and I don't like how you can't swim in the water.
New Pork City - this my #1 least favorite stage. It's waaaaayyy too big. So big, it takes about 3 times as long to play through than other stages with stock. Plus that monster is annoying.