I thought about this too...
There are some folks who do steal a movie:
1. Morris Day - "Purple Rain" - When all was said and done I'd rather have heard Morris Day and the Time than Prince and the Revolution.
2. Don Cheedle as "Mouse" in "Devil in a Blue Dress" - Cheedle stole every scene with his understated presence and power in this movie. Underated mystery movie.
3. Richard Widmark as "Tony Udo" in "Kiss of Death" - When he's on the screen no one remembers Victor Mature at all.
4. Javier Barden as "Anton Chigurth" in "No Country for Old Men" - I've never felt someone COMMAND such presence on the screen in my life. He wasn't just a "villain", but a force of nature. Part Hannibal Lector and Frankenstein Monster all rolled up in one. In the end I wanted the camera to just keep following him.
5. Daniel Day Lewis as "Bill the Butcher" in "Gangs of New York" - Much like Chigurth above Lewis is "larger than life". Nothing stands in his way, none can stand against him.
6. Dennis Hopper as Frank Booth in "Blue Velvet" - I guess you can see a pattern here.
Those are all that I can come up with off the top of my head.
Da Worfster