I ended up visiting denver for vacation last week.
I had a great stay there, I stayed downtown for the most part but not entirely. First off, DIA is by far the nicest airport I've every been in, reminded me of a mall. I enjoyed the fact that Mountain Like elements were almost everywhere I went in the design of buildings and things like that. I was really shocked at how clean the city was for a city that size. Seemed like lots of outdoorsy things for people to do.
I visited 16th street repeatedly while I was there and was utterly shocked at how vibrant it was even when the weather wasn't the nicest, really a great system with the FREE ride. I visited the state Capitol, The Aquarium and Platte River Walk, The Main Library, the fantastic Art Museum, Science Museum and Planetarium. I rented a bike and went around the Cherry Creek area and rode through some really great neighborhoods and then city park. Visted the Lakewood and Golden areas as well as Colorodo Mills/Coors Brewery and rode up into the mountains a bit. I had a great time and will definitely be returning for more trips to the area.

Everyone I talked too was really nice, and really helpful also. Glad I took the trip there. And can't wait for the next time.