1. Anything New Holland makes is amazing!
2. Bell's Naturally but I usually stay focused on Two Hearted Ale and their Amber.
3. Olde Penisula in downtown Kzoo has a very good Pumpkin beer on tap and I like their ChocoStout as well.
4. Jolly Pumpkin
That's it for me but I'm watching this thread to try some others.
Well Im a huge fan of the bells amber, all the founders stuff is good. And a not so well know brewery in bay city, mi, Tri-city brewing, make a great helles called helles half mile.
Downtown Detroit has three great totally different brewpubs:
Detroit Beer Co - Polished bar food, great beers brewed. Try the Detroit Dwarf or whatever the seasonal is.
Motor City Brewing - Small hole in the wall near Wayne State. Incredible wood fired gourmet pizzas, and pretty good beer too. Ghettoblaster English Mild has a pretty unique taste.
Traffic Jam and Snug - Older than dirt near Wayne State. Super eclectic ambience and menu (with great vegetarian options too). They make their own beer, bread, cheese and ice cream on site. Usually only 4 beers on tap though, and they rotate often.
There's also Atwater on the east end, but I don't care for it as much particularly.