In Michigan, The Henry Ford (Museum and Greenfield Village) in Dearborn; needs two days to appreciate both, have visited each at least ten times over the past 60 years.
Mackinac Island for a day or two. Soo Locks, if you've never seen a lock operation.
In Wisconsin, I like to revisit the Baraboo area, Devils Lake and the cliffs of the quartzite syncline. Of interest to geologists primarily, but also big with rock climbers.
Near Baraboo, people have been going to the Dells for at least 100 years, that's still an interesting experience, though it is now more a tourist trap than a natural wonder. There is a circus museum in Baraboo, as this was the off-season home of one of the traveling shows.
Texas, my favorite place to revisit is San Antonio. That's about the culture. Then there is Fredricksburg in the Hill Country west of San Antonio - San Marcos - Austin. That's about a couple different cultures, German heritage and ranching.
Texas scenic spots include the Davis Mountains and Big Bend area in the southwestern part of the state, Palo Duro Canyon in the Panhandle. But what I like most about the western part of Texas is just the way it spreads out in front of me, seeming forever. But western Oklahoma, Kansas, eastern Colorado are like that too, maybe 30 years living of the prairie has made me a prairie person. For most people, prairie is something to cross as quickly as possible, maybe at night so you don't get overwhelmed by endlessness.