There are far more than I have listed, but many of them don't do this on a regular basis and have little to no information available online.
Cobblestone Farm in Ann Arbor is a bit more elegant and has a ramp to allow guest easier access to the barn. I've also done a few events here, including an outdoor ceremony. http://www.a2gov.org/departments/parks-recreation/Pages/default.aspx
Ellis Barn in Oakland County is a historical barn and was relocated from Clarkston. I've done one wedding here and the upstairs area was where they held the ceremony.
And finally, Red Tail Farm is one I have not been to yet, but I have a wedding booked there in October. http://www.theredtailfarm.com/
Omega Farms is a working farm in Williamston. If you don't mind the BYO everything, then this spot may be perfect for you. It turned out to be a really nice location. There isn't any wedding information, but if you look on their calendar, they are still doing weddings occasionally.
Lazy J Ranch in Milford is OK, but I would make sure you get EVERYTHING in writing and don't let them offer to do square dancing unless you're alright with them taking up a lot of your precious dance time and watching a lot of guests leave early. See my review here.
Lastly, check out this link which has good information from a few I've never heard of.