Here's how I think the list should look like:
Neutral:
Final Destination - Nothing wrong here except campers and the annoying lips on the ledges, but those could be dealt with through skill.
Battlefield - Probably the most neutral stage ever. Size is perfect, not too camp-friendly, perfect ledges, etc.
Smashville - Also completely neutral. Nothing wrong with it.
Yoshi's Island (Brawl) - Nothing wrong with this stage except the support ghost, which actually helps more than it hurts.
Lylat Cruise - Tilting here is very minimal. Sure, it ruins auto-cancelling, but only for a very short duration. This stage should still remain neutral.
Battleship Halberd - Stage hazards are REALLY easy to dodge, and you could even use them to your own advantage if you have enough skill.
Pokemon Stadium 1 - This was neutral in Melee, and should remain neutral in Brawl. Just a simple size reduction won't do much harm.
Counterpick:
Castle Siege - Temporary walk off ledges make me think of this stage as a counterpick instead of a neutral. I swear I hate walk off ledges. Also, the second phase of this stage is a little too big. Fast characters could run away.
Frigate Orpheon - Right ledge is hard to grab on to and you're screwed if the stage turns upside-down while you're trying to recover. Still very fair aside from those two problems, though.
Norfair - Lava can be dodged with enough skill, but sometimes there's just TOO MUCH lava. Also, the fact that there are three ledges on each side doesn't really feel right. Still a playable stage, though.
Brinstar - The acid/lava is the only thing keeping still stage from being neutral in my opinion.
Pirate Ship - Many stage hazards, yet they're all very easy to dodge. Even the bombs aren't all that bad. The swimmable water, though, is the problem. Characters that rely a lot on spikes, such as Falco, are gonna have a pretty hard time KOing people here.
Delfino Plaza - Temporary swimmable water and walk-off ledges keep this stage from being neutral. Still, everything else about this stage is neutral.
Mario Circuit - Annoying walk-off ledges, and karts come a little too often despite being easy to dodge. Still playable, though.
Luigi's Mansion - Just some non drop-through-able platforms keep this stage from being neutral.
Pictochat - Playable, although stage hazards come a little too often.
Jungle Japes - Thankfully the water's actually swimmable unlike in Melee, therefore making this stage playable. The current of the water, though, is still a little too strong.
Pokemon Stadium 2 - Electric transformation has some really annoying edges, Flying transformation stalls the match, and Ice transformation has some really low traction. Still, most of this stage is playable.
Rainbow Cruise - Playable, although you'll have to put some effort into the moving rather than focusing 100% on the fighting.
Yoshi's Island (Melee) - Not too big anymore, and the three blocks in the middle aren't as threatening. Take note, not AS threatening. They could still cause death in some situations. Also, I hate that up-hill slope on the right side.
Shadow Moses Island - Playable, despite the temporary walls on either side and the annoying walk-off ledges. Characters still have the option to star-KO here, though.
Green-Greens - Explosives, the tree, and apples are all not as threatening anymore, although they do get very annoying sometimes.
Onnet - Cars sometimes don't give enough warning, too many walls, and annoying walk-off ledges. Still not enough to get this stage banned, though.
Banned:
75m - Too big, feels too restricted, items pop out of nowhere, walk-off ledges on the right side.
Big Blue - Come on, everyone knows why this should be banned.
Bridge of Eldin - Too big, too camp-friendly, walk-off ledges on either side, bomb kills way too easily, gap between sides (when the bridge is destroyed) is a little too big.
Flat Zone 2 - Stage hazards have some incredibly high knock back.
Green Hill Zone - Curve in the middle negates a lot of combos, splits a little TOO randomly, walk- off ledges.
Mario Bros. - Pretty much impossible to KO people here.
Mushroomy Kingdom - A lot of characters can simply hold you against a wall and let the scrolling finish you off.
New Pork City - WAAAAAAAAY too big! Even worse than Hyrule Temple.
Port Town Aero Dive - Cars are hard to dodge and KO at very low percents.
Rumble Falls - Scrolls way too fast despite the warnings given. Also pretty freaking big.
Skyworld - Too many walls, platforms can't be dropped through, gives major disadvantages to tether-recovery characters, matches here last way too long.
Spear Pillar - Cave of life, really big and annoying loop, too chaotic.
Summit - Annoying loop, swimmable water, and most of all, the stupid, random fish that pops out of nowhere and KOs you with ease. I hate that fish.
Temple - Too big, cave of life.
Warioware - Way too chaotic, forces people to focus more on the mini-games rather than the fighting.
Still haven't decided on:
Hanenbow
Corneria