STEALS the film completely in Layer Cake.
I must admit I haven't seen this guy in many movies. Guilty as charged. But I still wanted to add some variety to the "DUMBLEDORE!!!1!!" posts.
Layer Cake is a personal favorite movie of mine, my second favorite of all time. Daniel Craig as the nameless drug dealer is pitch-perfect, but Michael Gambon, by the time he shows up in the film ('bout halfway through?) completely steals all the scenes he's in. Plays the kingpin (not sure how to describe his character) perfectly.