I do not live in that area, but thing that has brought my wife and I up there a few times are the water falls, I think there are something like 101 falls in Michigan, 99 in the Up.

Then there is Big Spring (Kitch-iti-kipi).
This is neat because you pull yourself across the lake in a glass bottom boat.

Oswalds Bear Park is pretty cool as well.

White fish bay you can go out in a glass bottom boat to look at ship wrecks. They say if you drained the lake, you couldn't look anywhere with out seeing a wreck.

Of course the straits..

That's all I can think of in 20 sec's. I will be back..