Last of the Mohicans, Heat, Manhunter and Thief are all classics. What I like about Mann's stuff is so often he manages to show true expertise/professionalism from both the good guys and bad guys in a away that elevates away from being just a crime drama or thriller or historical action film. What I like is you get a sense these guys earned their expertise, and it isn't they are just "badass" or whatever.
I enjoy Dr Strangelove, but Paths of Glory, Clockwork Orange, 2001 and The Shining surpass it. I kind felt that Eyes Wide Shut was one of his weaker efforts but probably should watch it again - I may have gone in with too high of hopes as it had been so long since Full Metal Jacket and I was getting all his films on disc at the time.