Dio Brando because nothing is better than a vampire that stops time and drop steamrollers on people.
Doubt there is a better villain before or after. :)
Kaiser Soze. The ultimate under estimated underdog
MegaTron from Transformers - he was a bad *** in his own right and always created havoc. Reminds me of when I was a little 'un :P
yes he is, especially in the scene were he is dressed up as a nurse and blows up the hospital.
Voldemort from the Harry Potter series. Guy was cold, calculating and will tell you to your face that he's going to kill you. I also loved how everyone was scared to utter his name because he was just that freaking scary.