up in the air disc golf is a nice store in waterford. they have a large used selection(including many collectibles and rarer stuff on the wall). they also have a good selection of new stuff most of the time. i say most of the time because they are pretty busy. they get big orders in and people buy stuff pretty quick. they carry just about every brand i can think of at least some of the time. they also have clothing and other equipment.
karma junky is ran by a really cool guy named paul. it is located in his machine shop behind the buffalo wild wings in grand blanc. he always has a good selection of the big names and at least some of the lesser knowns. he also has some used stuff and other equipment at good prices.
both shops are worth checking out.