The museum at Whitefish Point is well worth it if you're into history. I thought it was definitely worth paying for the full tour. Tequamenon falls is scenic. Oswald's bear ranch is pretty cool.Watching A freighter go through the locks at Sault St. Marie is pretty cool. If you want to eat at a pretty awesome place, heading southeast along the rivet out of the Sault you can find a place called Cozy Corners... great food and an awesome display of all sorts of taxidermy. Like the others said, Sleeping Bear Dunes to Manistee to Ludington is a great area for beaches, lighthouses, pier fishing, you name it. If you make it to Ludington, heading out on the pier and watching the Badger head out is cool. These are a few I can think of.

Greg