Great breweries mentioned so far.

Horse and Dragon is fantastic, Equinox as well.

for german style beer Prost in my opinion makes the BEST in the country. Grimm Brothers is good, but less traditional in the sense of "german style"

I really like Pug Ryan's beer, but only tried a few of their beers from the stores. Dillon is a bit of a trip from Fort Collins, but their Dunkel is so good!