Bravo, Mint Museum - your exterior matches your interior. This museum is quite shiny and new with seriously stunning exterior, super clean facilities and a few very interesting galleries.
With my parents in town and in tow, we started from the top and walked through the handful of galleries, making our way down. I really appreciate the audio tours that are accessible via cell phone. Be aware that only one piece per room (roughly) offers an audio tour - which is very cool. I kinda wish there were more audio tours available. Regardless, these cell tidbits made the experience that much more enjoyable as I stalked through the galleries.
Some of my favorites include the Charles Clough collection, Ansel Adams display, a special Norman Rockwell piece and two very interesting lithographs, "Cindy" and "Gretchen" by Robert Longo. I probably spent 1.5 hours walking through (one gallery was closed due to a new installation) and thoroughly enjoyed it. It's definitely worth checking out!