Two of my favorites breweries would be Oskar Blues in Longmont, CO and Avery brewing in Boulder.
Avery Brewing Company
http://www.oskarblues.com/
My favorites Oscar Blues brews would be the Gubna Imperial IPA and the Ten Fidy stout. But not to many as both are in the 10% content range.
And when I'm in Boulder I always have to stop at Avery's for a White Rascal or a Czar's Imperial when it is in season.