Denver is the closest big city to where I live, so I’ve been there rather frequently. There’s lots of nice things to do there.
The Denver Center Theater won a Tony for regional theater and I’ve enjoyed every play I’ve seen them do. In the same performing arts complex the opera, ballet, and traveling companies of Broadway shows also perform.
The Tattered Cover bookstore is the bookstore that Barnes & Noble ripped off when they started. If you’re in Denver, see the original in the Cherry Creek shopping district and see why 4 floors of books are better than one.
The Denver Art Museum, while currently being expanded so they don’t have they’re usual capacity, is a fantastic art museum and hosts great permanent collections as well as excellent temporary exhibits.
The Denver Museum of Nature and Science is a good science museum, and right next to the Denver Zoo. I suggest if it’s a nice day going to the museum, and if it’s cold and windy throwing on a coat and going to the zoo. That way you avoid the school children.
If kitsch and South Park and bad Mexican food are your things, you may want to eat at Casa Bonita .