According to MI's travel and tourism
site, there's four breweries in Detroit proper, and a bunch more in the burbs.
Not brewery related, but for my buddies bachelor party in the D a couple years ago, we hit up Garden Bowl
. For 23 bucks a person, they give you three hours of bowling, food, and as many pitchers as you can drink. Granted, it's pitchers of Bud Lite or something similar, but we had a blast.