Summit was an early midwestern microbrewery, and the beer was nice, but I wasn't overly impressed. I'm sure they've introduced some newer stuff since I was last in the Cities.
I believe my favorite Wisconsin brewery, Tyranena, is selling in the Cities now. Look for their Bitter Woman IPA. They also do a quarterly "Brewers Gone Wild" release. In the past their "Bitter Woman from Hell" and "Hop Whore" IPAs have been impressive (the latter, which hoppier and higher in alcohol, was the best balanced of the bunch, according to me).
This evening I had a Stone Arrogant Bastard on tap, which was pretty good. Even better was the New Belgium Ranger IPA. I didn't expect much from the New Belgium, since their flagship beer is the popular but meh Fat Tire, but I was pleasantly surprised.