If you have time and you really want to get creative, there are at least a dozen brewpubs within easy Metro Denver reach that have limited edition bottled beer that is most excellent. Trinity and Phantom Canyon in Colorado Springs, Moujntain Sun/Southern Sun, BJ's, Walnut in Boulder; and if you are heading up north to Ft. Collins take a detour to Longmont and catch Left Hand, Oskar Blues, and the Pumphouse. Oskar Blues - the restaurant - has some 21 taps. . . the Bourbon Ten Fidy was my nirvana. There are just so many choices and though NB and Fat Tire are good staples, it is exciting to check out some smaller operations. If you are confined to Denver then I would hit up Wynkoop and there are two great Rock Bottom brewpubs that always have something unique, though a chain, each has the latitude to go off and create. Rick Abatol at the Rock Bottom at I-25 and County Line (just before 370) is especially adept at doing one-of casks.
Gawd, I miss Colorado!