STREET FIGHTER IV

When starting up an arcade game, you will have to move the difficulty all the way to the right until you reach "Hardest." From here, it's all up to you. Things to note.

-The time limit and round limit is entirely up to you. So, if you want one-30-second-round-to-win matches, that's good.
-You can continue if you lose, so don't worry about anything if you happen to get beat up a lot.

Unfortunately, I can't comment about how difficult this achievement is because there is a super-cheap way to get this which I decided to use. This will make things a lot easier for those who want the achievement but aren't exactly pros at the game.
Start up Arcade mode on the Hardest difficulty with 1 round to win, and 30 second rounds. When you choose a fighter, stick with Zangief. Zangief is a pretty powerful character to begin with, but if you press LP+MP+HP at the same time (LB with default controls) he does a spinning liarat move that makes the computer act stupid. He also has a faster version of this (albiet weaker) by pressing LK+MK+HK (LT) at the same time.
This move is pretty cheap since he does a good deal of damage on enemies and it also knocks them down. When they start getting up, press LB again and repeat the whole process. Now, if you're doing this method you will have to keep on defense since you won't always K.O. your opponents. Their revenge meters will fill up and they will use those moves in a heart beat. I'd say stick to three LB presses and then block for a bit, then repeat.
Seth mighty pose a problem, but for him it's all about dishing out whatever damage you can right away and then blocking like a madman until time runs out.

Using this method, you should be able to get this achievement in no time. This method also works for the Arcade Rat and Save Your Quarters achievements (beating medium, and beating medium w/o continuing).