Doug,
I'll only talk about courses I've played.
Iowa:
*The Harvester - For sure, great course and a different style of design.
Minnesota:
*Giants Ridge (Quarry) - a good course but not a great course.
*Hazeltine National - allows sponsored guests for the tune of $200, although unless your into playing a "majors" type course for the mystique, it's not worth it.
Wisconsin:
*Lawsonia - I'm not into this whole place although people on this site think it's better than Whistling. If you're within an hour of it stop by, if not, don't bother.
*Whistling Straits (straits) - a must play if you haven't played it once yet.
*Whistling Straits (irish) - if money is an option go with the Irish course, very solid course and highly highly underated to most "naturalists" on this web-site.
*Blackwolf Run (river) -great course, worth the money once
*Bull at Pinehurst Farms - not worth the money if you're in the Kohler area, just pony up for one of the Whistling courses
Michigan (i'll only highlight the ones you should play since I've played them all):
*Greywalls - play 36, for sure...2nd best public in state
*Arcadia - great course and worth the $180, best public in state
*Forest Dunes - great course, 3rd best public in state
*Eagle Eye - only $60 after 3:00, a great track
-Brian