As Jay mentions, there are too many to name but one movie that I really like for it's dynamics over the course of the entire film that often gets over looked with all the SFX driven movies is "Forrest Gump". It really is an exceptional sounding movie that is mixed very well. It has really soft moments, to very punchy and loud (but clean) during the Vietnam war scenes. The score is wonderful and really pulls out the emotions during the movie, and scource music cues are great for tying in the historical eras of the story.
I also really like Contact, Fight Club, Heat, and The Phantom Menace. All "JarJar" jokes aside, it's one of the tightest mixes I've heard.