I was going to mention Jackie Brown too.
Casino is one of my favorite films. The impossible love story at it's center is as close as Scorsese will get to transmit "love" from a man to a woman in film. The cinematography is one of it's biggest assets. It's probably the film that takes the most advantage of the Vegas visual possibilities, in history.
Scorsese is in full power here. Visually it's such an inventive film, via mise en scene, compositions, just the way it's designed. He never came back to this kind of visual storytelling again.
The other aspect that always surprises and fascinates me is the soundtrack choices. Loved the way he uses the Contempt theme, and the film is filled with great "musical" sequences.