Sephiroth #1: Threatened to destroy the world. Made the sky turn black. Smashed Cloud Strife into a building and stabbed him in the shoulder. Made an entire building fall down using his mind. Sword contains powerful magic. Killed Aeris. Hates everything in the world.
The Emperor #3: Only gained power through political corruption. Idiotically kept on using force lightning on Mace Windu, while taking all the damage himself. Can only use force lightning and lightsaber. All his apprentices were defeated by Jedi.
Voldemort #5: Only killed Harry Potter's parents, and couldn't even kill a baby. Only concentrates on killing Harry Potter.
Sauron #2: Created the One Ring, filled with hatred, malice, and his will to dominate all life. Killed Men and Elves in waves with his mace, and the Ring of Power. Killed by Isildur after a simple finger cut, but still very powerful.
Agent Smith #4: Simply a being who just wants to take over the world and made so many copies of himself.