I present the:
No Johns Competitive Stage List
This stage list runs off of the philosophy that stages have no reason to be excepted from the ban philosophy followed with everything else; a ban is a last resort and only warranted when leaving the offender allowed would destroy competitive play. A stage being annoying to play on is not a valid ban criterion.
Reasons a stage should be banned:
1. The stage makes one (or a very small amount) character or strategy overwhelmingly powerful so as to devolve the game into a competition of who can abuse said character or strategy the best.
2. The stage promotes camping in such a way that the timer will run out nearly 100% of the time. This restriction is primarily called because of tournament time constraints; tournaments do not have an infinite amount of time, and all matches cannot realistically be allowed to take the full eight minutes.
3. The stage functions in such a way that a fair, competitive match on it is rendered impossible.
STARTERS
Smashville
Battlefield
Final Destination
Yoshi's Island (Brawl)
Starters are intended to have as little effect on the outcome of the match as possible. All stages listed here should be self-explanatory.
I'm a fan of a conservative starter list so as to preserve the most neutrality possible in the first match, but it can be argued that Lylat Cruise, Delfino Plaza, Pokemon Stadium 1, and Castle Siege have a small enough effect on the match that they can be allowed as starters.
COUNTERPICKS
Delfino Plaza
Delfino Plaza has many areas with walls, water and walk-offs which have enough effect on the match to not be allowed as a starter, but certainly not enough to be banned.
Norfair
Norfair is a hate-it-or-love-it stage and a popular counterpick in tournaments where it's allowed. The hazards are trival to avoid, and its multiple edges have yet to create any unstoppable strategies. Counterpick.
Frigate Orpheon
The stage flipping mechanic and the lack of a ledge on the right side of the first formation make this a counterpick.
Halberd
The way the main platform works favors some characters more than others enough so that this stage becomes a counterpick instead of a starter.
Lylat Cruise
Lylat Cruise's shifting ground and whoops-there-goes-your-stock ledges make it a counterpick.
Pokemon Stadium 2
This stage is banned in a lot of tournaments and I still don't know why. The one offender on this stage is the wind transformation, and it doesn't last long enough to force a stall-out on the stage. Counterpick.
Port Town Aero Drive
The cars on this stage are very strong, but also very easy to see coming. Aside from the cars, the lack of ledges on the main platform puts characters with poor recoveries at a disadvantage, but not nearly enough to be worthy of banning.
Castle Siege
The only thing stopping this stage from being a starter is the second section's walkoff blastzones.
Distant Planet
I have no idea why this stage was ever considered for a ban. Do people just hate Ai no Uta that much? The walkoff is easily avoidable and often unusable due to the rain, and the only thing that you could call a hazard is one of the most glaringly obvious and incredibly easy to avoid hazards in the game. This stage is the definition of a counterpick.
Skyworld
Skyworld's janky platform setup effectively puts any character lacking a decent recovery at a disadvantage, but the majority of Brawl characters do have decent recoveries. Spiking people through the bottom is not an unbeatable strategy, either, nor is it powerful enough to upset the balance of the game enough for this to be banned. Counterpick.
Pictochat
The only valid concern with this stage is the few transformations where camping/stalling is heavily promoted, and they don't last nearly long enough for this to be a problem. Counterpick.
Yoshi's Island (Melee)
The permanent looming threat of getting chaingrabbed off the right side almost led this stage to be banned, but attacking the boxes in the middle and staying on the left mitigates it enough to be allowed as a counterpick.
Jungle Japes
The campiness if Jungle Japes has long been a point of contention, but it fails to reach the level of violating reason 2. The Klap Traps and quickly-moving water offer a unique offstage game that isn't offered elsewhere. Counterpick.
Onett
The cars appear often enough for wall infinites to become merely a good strategy rather than an overwhelmingly powerful one, and getting chained off the sides is fairly easy to avoid given the layout of the stage. Counterpick.
Rainbow Cruise
Rainbow Cruise is a stage that largely favors characters with a strong aerial game, but not to the point of overpowering them. The walkoffs and wall infinites are avoidable and don't last too long, and camping is largely a non-issue. Counterpick.
Green Greens
Green Greens' one main problem is the possibility of wall infinites that are opened up by the blocks falling on either side. The ability to keep the blocks destroyed, though, keeps it from becoming an overwhelming strategy. The small stage boundaries and unique layout lead it to be a counterpick.
Brinstar
So far, Brinstar's lava and unique stage layout hasn't made for any overpowered strategies, and camping here is fairly difficult due to its small size. Counterpick.
Pokemon Stadium
Pokemon Stadium's walls and occasional campy transformations make it a counterpick.
Rumble Falls
Ah, Rumble Falls. This stage is banned nearly universally because the way the stage functions immediately puts off most of the community, but I believe it's worth a second look to see if it actually merits banning or not. The few walkoffs and walls it has don't last long enough for chaingrabbing to become overpowered, and it serves as a strong counterpick against characters with a strong ground game like Snake and King Dedede. There is one issue which calls for attention, however: the ease with which the timer can be stalled out. In my own testing of this stage, I've seen that matches here typically take longer due to the forced aerial game and tendency for players to wait until the stage layout favors them before approaching. To my knowledge, though, no major tournaments have allowed this stage, so there's little evidence of how this would affect a tournament atmosphere. This stage list goes by "innocent until proven guilty"; as such, Rumble Falls is a counterpick pending further evidence.
Corneria
The permanent wall here offers immediate concerns, but it is avoidable and camping it in the hopes of getting an infinite puts you at the risk of being hit outside of the alarmingly close blast zones on that side. There is another issue, though, involving how powerful Mr. Game & Watch is here. His bucket can be freely filled here with powerful lasers, giving him a quick one-hit KO which he can abuse whenever he so chooses. Although this could potentially break reason 1, I haven't seen enough tournament evidence to prove whether or not Mr. Game & Watch is too powerful here. Counterpick pending further evidence.
Big Blue
This stage is an instant ban for many due to its constantly changing layout, instant death road and frankly uncomfortable playstyle, but I don't see why any of those factors merit a ban. This stage forces a change in playstyle from the usual stages, but there are no largely dominant techniques here thus far. Stalling is a concern; the stage has large blastzones, and hopping from object to object until the timer runs out isn't totally unrealistic. Despite this, the amount of high-level data on this stage ranges from very very small to none, so nothing has been proven. Counterpick pending further evidence.
Pirate Ship
Pirate Ship is notable for its strong hazards and being the only stage with a distinct water game, but neither of those are strictly bad things. The tendency for water camping to run out the timer, however, brings this stage under violation of reason 2... perhaps. The extents of all the characters' water strategies and counters against them are still largely unexplored, and major tournament data is fairly scarce. To be a counterpick or banned pending a TO's discretion or further evidence.
Luigi's Mansion
A controversial stage. Luigi's Mansion skirts the edges of reason 2, combining large blastzones, a pseudo cave of immortality, projectile-stopping pillars and elements of circle camping into a stage where the timer can be run out very easily. It's not overwhelming enough for stalling to be the only strategy, though; the mansion can be destroyed, at which point the players will run out of places to run, and the stage itself offers a unique dynamic that other allowed stages do not. This stage can be allowed as a counterpick or banned pending a TO's discretion or the attendance of Plank.
Green Hill Zone
Green Hill Zone flirts with reasons 1 and 2 like a cute checkout girl, but it tries to flirt with them both at the same time and ends up sending some very confused messages. Chaingrabbing is very powerful here, except when the checkpoint is up, at which point camping behind it and spamming projectiles becomes the winning strategy. Both the stalling potential of checkpoint camping and the killing potential of chaingrab spamming counteract eachother and make for a very weird match where stocks can be lost with one move yet most of the time is spent camping. Given this weird dynamic, this stage can be allowed or banned pending a TO's discretion.
BANNED
Mushroomy Kingdom 1-1 and 1-2
Both of these stages exhibit the same flaw; chaingrabbing and wall infinites are the strategy here, violating reason 1.
Mario Circuit
The winner is King Dedede. It is nearly impossible to avoid getting chaingrabbed out of the stage, breaking reason 1.
Bridge of Eldin
See Mario Circuit. In addition, matches almost never finish on this stage without the timer running out.
Spear Pillar
Spear Pillar's layout almost forces circle camping in a competitive environment. Banned under reason 2.
WarioWare, Inc.
WarioWare is damned by its one flaw of having randomly-picked awards for completing the microgames, bringing the possibility of one player getting a star while the other gets a megamushroom, despite both of them having done the exact same thing. This is the only stage banned by reason 3.
New Pork City
This stage is intensely circle-campy and no one ever dies here. Banned under reason 2.
Summit
See Spear Pillar.
75M
See New Pork City.
Mario Bros.
On this stage, you can either fling hazards at your opponent, chaingrab them out of the screen or lose. Banned under reason 1.
Flat Zone 2
See Mario Circuit.
Hanenbrow
See Spear Pillar.
Shadow Moses Island
See Mushroomy Kingdom.
Hyrule Temple
See New Pork City.
Post your objections and I'll probably consider them briefly before writing them off and calling you a scrub. This is a work in progress and needs input from someone other than myself.