Boss: M. Bison
Game: Street Fighter Alpha 3
How To Beat Him/her: Arguably the toughest M. Bison to ever exist, this version had a deadly attack called the "Final Psycho Crusher," a move that envelopes the entire screen in blue flames, and deals severe damage to Bison's opponents.
And to add to his difficulty if, you lost to Bison, you had to start the game from the very beginning. That's right: no continues. To make sure that doesn't happen, use either Ryu or Ken and utilize their spin kick attack, and their uppercut attack. Since Bison teleports a lot, be careful to not use your special attack at the wrong moment.