My favorite overall baddie is the Emperor Palpatine. He gave a great speech when he declared the beginning of the first Galactic Empire. He just looked so happy and so full of himself! Of course, I am also a big fan of Darth Vader, especially when he promotes subordinates or accepts appologies from them!

I do have to mention my favorite Star Trek baddie - Gul Dukat, from Deep Space Nine. He was great to watch. He so loved being bad; the speech he gave when he declared martial law was especially memorable.