I assume you'd probably be taking the I-80 route the majority of the way. If thats the case, there is Thunder Mountain in Imlay, NV and the Ames brother's Monument in Buford, Wyoming. Both of which are a relatively short distance off of I-80. The Ames monument is just a giant pyramid in the middle of nowhere. Also, if you have the time, you can make the journey up to Alliance, NE and visit Carhenge, a replica of stonehenge made completely out of cars. Roadsideamerica.com has articles on all three.

In terms of food in Denver, CO, I don't know if you've heard of the show Man VS Food but the host did stop at a few different places there. They're listed here:
http://www.travelchannel.com/TV_Show...vgnextfmt=show