I was only in Denver for about four days. First stop was the "Ocean's Journey" exhibit. Highly recommended, even more so if you're a fisherman like me - you'll oogle at the trout for ages. I also visited the Museum, did the IMAX movie thing (Shackleton's journey is brilliant)
Just walking around the city is a lot of fun. In the main mall, there is a little shop off to one side called the "Knox Gallery" which seem to specialise in bronze sculptures, a lot of which are dotted around outside the shop. Some of them are a little strange for me, but some of them were brilliant.
The airport is nice too. (I got to see a lot of airports)
Next (Las Vegas)