I can think of at least 14 onscreen evil Time Lords, and I'll even allow ones from audios as long as they can be verified. Normal AV rules apply: Max image size 200x200px / Max file size 1MB I'll take entries till at least Sunday evening. I'll get the ball rolling.
If there's one thing I learned from Gary Oldman's appearance on Friends, it's that spitting while speaking equals good acting.