For those who don't live Colorado, Left Hand has been hyping up their release of their milk stout bottled with nitro, not CO2, it's very good pours like a Guinness.
Oh and Fresh-craft is a great place for great craft brews and food when in Denver,
If you happen to venture north to Fort Collins, stop by The Mayor of Old Town (100 beers on tap) and great food, plus there now like 8 or 9 breweries/brewpubs in town