Added powershielding, multi directional input, morph jumping, rocket down smash, and robo thunder.

@ Sachamel: That would be great. Making gfys is super simple, just go to gfycat.com and follow the upload instructions. It accepts a variety of video formats as input, including gifs.

@ Huey: Great! I'll convert them to gfy and write up a dash canceling entry tomorrow. I hope you don't mind me changing the name of MDA to MDI, I felt it was more appropriate since it isn't strictly necessary to approach while using it.

I actually like the name MDI more. Nice idea

Aw man, I hope this topic doesn't die. Aren't DI and SDI considered ATs? Someone SDI educated should make a list of the most commonly used SDIable moves. Maybe they can also answer for me if you can SDI Fox's uair. I always wondered.

Anyway, maybe the next step of this thread is to make a video series of each AT with a good amount of examples for applications and mixups.

Fox deserves a place in Character-specific techniques.

Fox

1.Specialized Lasers (Dunno what to name it, but you can always think of a better name)
Example: http://gfycat.com/SimilarMerryAllensbigearedbat
http://gfycat.com/UnfitWholeClingfish
Who says lasers are useless in SSF2?
Characters that you can perform on: Black Mage, Sonic, Sora and Megaman.
Description:If you hit BM with laser while he's using his up-b, his teleporting "ring" will disappear and he will teleport to his very own spot, being in helpless state, making his biggest mistake ever not to recover down the ledge.
Sora, Sonic and MM is a different story, probably useful in teams. If you hit any of them with laser while in up-b state, they will gain one more up-b to use. You will have to hit MM AFTER he initiates his up-b to reset the recovery. Repeat this to help your teammates get back on track.


Method:
1. Wait for your opponent/teammate to use up-b offstage.
2. Hit him with laser.


2.Sneaky Pinch-hitting
Example: http://gfycat.com/EdiblePertinentGreatargus
Description: This technique is really useful in both neutral and competitive play. Fox dashes to the edge of the moving platform of Smashville and does a spotdodge. This gives him invincibility until he gets up. Your opponent will be confused by seeing you lying like this (unless they know what's going on) and will mostly come to you to hurt you. Then you can use force get-up to deal some damage. You can even avoid a final smash with this technique. The floating platform over Smashville isn't the only platform you can perform this technique on. Just slightly better. You will need perfect timing on other platforms though.
Method:1. Dash to the edge of platform.
2. Do a spotdodge.
3. In order to spotdodge, press the down key while still holding the shield button. Don't hold the shield button while you are falling or you will forced to do the tech or tech roll
_______________________________________
Credit goes to Dopeness for mentioning the Laser gimping tech. Even though I found 1 month before he actually did, I did not mention it so he deserves the credit.

Here are some of the most-used SDI moves:

Peach's Dsmash (SDI up)
Kirby's DA (depending on location, usually up and behind)
Pikachu's Dsmash (SDI down and tech if you're a fast-faller, or SDI up to try an escape if you're not)
Screw Attack (SDI to the left or right)
Zelda's Smashes (to the side for usmash, away for fsmash)


Someone else can expand this list, but just learning these helps out a lot in their respective MU's.

I can't believe this hasn't been said yet.

Morphslide
Example: It features in this video a lot.

Metroid can crawl!
Description: Samus can move around freely in morph ball form for a brief moment of time.
Method:
1. Use the Morph Bomb right before you hit the ground. This is easiest to perform by doing the move while partially overlapping a pass-through platform.
2. Use the left/right arrow keys to move around until the morph bomb animation ends.
Uses:
This technique gives Samus a solid movement option, significantly shrinking her hitbox while allowing her to very quickly build up a decent amount of speed. Used on platforms, Samus has some nice setups by performing aerials off of the edges, allowing her to, say, approach with a falling reversed aerial without being super predictable about it by jumping 10 meters into the air first. By laying the bomb and moving away from the opponent at such a small size, the move works well at creating space between the players, which is always a plus for Samus. She also has the ability to repeatedly drop bombs off of an edge by running off, morph bombing towards the stage, rolling back a safe distance, and repeating ad nauseum. Or alternatively, increase her somewhat weak offstage edgeguarding game by following a dropped bomb with a falling aerial.

Also:

Crouch Cancel Dash Dancing
Example: Best example is probably at ~9:45. Yep, same video as before.

Description: Greatly increases the dash dancing length of any character, with only a slight loss of speed.
Method:
1. Dash forwards.
2. Whenever you want to turn around, use a HCB motion (forward, down, back) instead.
Uses:
Greatly improves mobility for those characters that have really bad dash dancing options. Can be immediately cancelled into any attack upon crouching. A decent option for baiting out moves.

Hurtbox

I'm claiming my throne as the hurtbox nazi.

[b]Name:[b/] Buffered Dtap Dashing
Characters that can perform: unknown , assumably all (not much time for testing)
Description: For any dtap dash users, they can still buffer the dash input as they land.
Method:
Just before you land, tap twice in the direction you wish to dash. When you land, you should instantly be dashing in that direction. Can be done with most SHFFs and after an up-b onto a top platform.


Also will like to note that the kioken glitch keeps his momentum with side b as well

I'm just going by what the game calls 'em. Hurtboxes are hitboxes, hitboxes are attackboxes.

Name Platform Bounce Cancel
Example(s): I will post it later.
Characters that can perform: The recent ones are on the list below.
Description: This can be used to cancel your airtime whenever you bounce off of Sonic's spring unto a platform and cancel into another move.
Method: It can be activated right before passing a platform. The catch, however, is that a "bounce" effect needs to be initiated beforehand in order for it to be preformed. It works on any platform whether high or low to the ground. This includes both stagnant and moving platforms.
List:
- Jump, Dair
- Jump, Uair, Bair, Dair, Nair, Neutral B, Side-B, or Down-B
- Jump or Uair
- Jump, Uair, Bair, or Nair
- Jump
- Jump, Dair, Bair, Uai, Nair, Side-B, Neutral B (both), Up-B
- Jump
- Jump
/ - Jump
- Jump
- Jump
- Jump
- Jump
- Jump
- Dair
- Jump, Down-B
- D-Air
-D-air
- Jump, Nair
- Dair

Would you at least put a description of what that tech actually does? You told us who can do it, how to do it, and I can somewhat imagine how it might look like, but you still gotta ell us what exactly it does.

What even is this? This has got to be one of the most terribly explained posts about an AT I've ever seen.

EDIT: Skailler Ninja'd me.

Uh....Just updated it.

Gif would be appreciated.

EDIT:

HOLY F#CK! Shouts to Zalo for this one. F#cking hell... It's like cheating with Bomberman lol #SHORYUKENJUMPCANCELHYPE