As much as I don't like brawl, I really don't like seeing noobs counter pick terrible stages for terrible reasons.
My stage theory follows a simple, but logical that makes sense.
A stage that hinders the fight between players in ANY WAY should be avoided. Now onto the stages...
NUETRALS
Final Destination - Good
Battlefield - Good
Smashville - Good, although I don't like the moving platform.
Yoshi's Island - Cloud is gay, but what can you do
Lylatt Cruise - Hate it, it spins/tilts, it undeniably messes up recoveries, plain and simple, and although it IS a very neutral stage, it's crap, grounds for a ban.
COUNTERPICKS
Halberd - Although I am generally against anything that disrupts or complicates the fight between players, this stage may be the only exception. The laser gun isn't hard to dodge, but the claw is, and it's far less obvious as to it's target/direction. Woulnd't disappoint me being banned.
Delfino Plaza - The way the stage starts is cool and neutral and all, but the different locations it stops at are gay with water and unever terrain. The transformation periods are akward and disrupt the fight too. Not somewhere I wanna play, wouldn't mind seeing it banned.
PokeStadium1 - The stage has had some minor adjustments, really, my biggest beef is the windmill is now TERRIBLE. The rock transformation promoted camping in melee, and now the windmill transformation does too. Not good.
DEBATEABLE
Frigate Orpheon - Hate it. The stage only has a ledge on one side. The stage flip, although given warning, can screw a player even if they attempt to deal with it. But they shouldn't have to deal with it to being with! Any stage that disrupts the fight should not be played on. BANNED!
Castle Seige - Transofrmation time is long and gay. Walk off edges are terrible. Destroyable terrain hinders a pure battle. Ban it.
Jungle Japes - Jungle Japes?? Are you serious? Debateable? This stage is complete garbage. BANNED!
Rainbow Cruise - Moving stages take away from the fight. I, myself, have not played on the stage even once yet. I hear it screws tether recoveries. Ban it.
Pirate Ship - Hate it. It really angers me that I have to make arguements for such painfully bad stages to be banned. The layout of the stage is horrible. 2 platforms on top f each other? Thats stupid. The spring board on the front kills, and just be a general pain in the *** and stage hazard. Water is bad, getting stucking in it leaves you a sitting duck, it prevents most off stage edgeguards too - not desireable in anyway fro a fair fight. The front end of the ship is a death trap. The back end has sailboats behind it or something, seems like a good place to camp. The canon balls are lame, deal large dmg and knockback. and appear to me as if they fire at random areas on the stage. It crashes into rocks or something gay... Then the ship flies up into the air!! Low gravity mechanics initiate, you can pretty much forget any type of aerial combat at that point, or any fighting at all. Do I really need to go on?
BAN BAN BAN BAN BAN BAN THIS HORRIBLE TERRIBLE STAGE FOREVER AND EVER.
Corneria - A camper's best friend. The wall/fin, allows players to live longer than they should. Ships fly in the background and shoot players, ships fly in the foreground and shoot players, guns on the base of the ship shoot players. None of that is desireable. Ban it.
Luigi's Mansion - I'm sick of seeing people counter pick this stage. I really hate it. As mentioned earlier by Kamano (and others im sure), the "cave of life" effect is horrendous, and this stage just amplifies it. Breakable terrin is terrible and annoying. "But you can destroy the stage and make it FD!" yeah, after 30 seconds and 10 attacks maybe. It's something that shouldn't have to be dealt with at all. BAN this terrible stage.
Distant Planet - Bouncing platforms, giant monster, falling item/seed/whatever things, walk-off edges, annoying rain. Bad stage, ban it.
Really.. i'm with Queen/others that said the same thing. If it ain't neutral, BAN IT.