Fighting You Is Such a Waste of Time
One of the most important aspects of Super Street Fighter IV is the Taunt, otherwise known as the "Personal Action." Well, okay, maybe they aren't important at all, but Taunts are still in the game and Taunts are still cool. They really are there solely for the purpose of being a Taunt: to show disrespect to your opponent or to signify that something weird really happened.
To perform a Taunt, just hit Hard Punch and Hard Kick at the same time. Interestingly, you cannot perform a Taunt unless the joystick is at Neutral. If you are holding any direction on the joystick, the Taunt will not come out. And keep in mind, when selecting the Taunt for your character, you can choose to not have a Taunt, so hitting this button combination does nothing at all.
Once you start the Taunt, however, your character will go into their Taunt animation, some of which are extremely elaborate. However, unlike in past games, you can actually cancel your Taunt before letting it complete, although every Taunt has a specific amount of time that it has to play out before you can cancel it. Each Taunt has their own window during which you are stuck in the Taunt, even between the different Taunts of the same character.
You're Boring the Crap Outta Me!
Some Taunts have some weird properties to them. For example, Fei Long has a Taunt which actually has him lie down on the floor. And this actually alters his Hit Boxes! He can actually lie down right under some Projectiles this way. It's not a particularly recommended way to get around Projectiles, but it is funny that they took these sorts of things into account.
Want Me to Go Easy On You?
Taunts fall into their own category of moves, they do not count as a Normal Move or a Special Move. So you cannot cancel any Normals into a Taunt any Taunting does not give you nor your opponent any Super Meter. They really are just Taunts.
Is That All You Can Do?
There are some special Taunts in the game. Dudley has the Victory Rose where he throws a Rose at the opponent that you perform by holding Down and pressing Hard Punch and Hard Kick. Performing the same code with Cody makes him do the Fake Bad Stone where he pretends to Throw a rock. This move counts as a Special Move, however, and you can actually cancel Normals into it. And finally, there's Dan, who has an extra Ducking Taunt that actually hits the opponent (but never builds any Super Meter up for either character nor does any actual damage), a Jumping Taunt, and, of course, his Taunt Super Combo: the Legendary Taunt. Unlike regular Taunts, all of these special Taunts cannot be canceled at all during their animations. Well... except for Dan's Super Taunt. Weirdly, the Legendary Taunt can be canceled at any time into an Ultra Combo!