OK so I'm a big time beer geek. My cellar currently has almost 100 different beers. Before I stated my Top 5 Midwest in no particular order is Great Lakes, Three Floyds, Victory, Bell's, and Goose Island. GoosIsland has a ton of variety, you just need to know where to find it. Being in Chicago, it's rather easy for me. Probably the best college for good beer in the Midwest is Michigan. It is a VERY mature beer market there. Ann Arbor Brewing does some very unique things. There are also 2 other brewers in town, plus easy access to Bell's and New Holland.
Ann Arbor also has the Beer Depot, a nice little beer shop dontown. The buyer there, Brian, is a HUGE Belgian fan (as am I). He regularly stocks a couple hundred Belgians and is one of the few places in the state to get bottles of Westy 12.
The east coast is also another haven for good beer. Boston as some nice brews and as you move to New York you have Ommigang, which does Belgian stule ales. Brooklyn brewers is also solid. The south sucks, not worth mentioning. Out west, WOW! Oregon is probably the craft brewery capital of the US. And of course in California you have the difficult to find Stone Brewery.
Well, I could go one for another day or so but that's it for now.