In Webberville(Between Lansing and Brighton on I-96), there's a place called the Michigan Brewing Company. There's about 12 different beers there last I heard. I like their Mackinac Pale Ale quite a bit. It's right behind the Big Mobil Station there at the expressway.
There's a Microbrew in Novi(Detroit suburb about 1/2way between Detroit and Brighton near I-96) that's good too. Local Color(I had their pale ale). Grand River(the main road that goes along I-96), just east of Novi Rd.
Big Buck in Gaylord(North Michigan) and Auburn Hills I've heard was good, but never had a chance to go there yet.
Bells is "alright" but a lot of people love it. They are based in Kalamazoo. I've only had their bottles, not draft though so that goes into consideration.