Ok if your trying to beat the hardest difficulty on super street fighter 4 the easist way is to select zangief as your primary charecter if your trying to do it fast or you want to try to do it without dieing I would suggest setting it to 1 round.

Zangief has two moves linked to two buttons i think their called double lariat and quick lariat or something real close to that either way their both linked to the

 ( on 360 one lariat is the LB and the other lariat is the LT buttons )

 ( on ps3 im assuming one lariat is the L1 and  the other lariat is the L2 buttons )

 This is a move that makes zangief spin and wil let him go through fire balls while spinning if you stand over an opponent because it will knock him down and time it correctly you should take almost no damage what so ever sometimes you will have to throw other things in their but u should be ok just smamming the two lariats.

Yes it is a cheap way to win but it works and over time is you get better you could win with the other charecters to but the easist way is with zangief.