Counties with the weirdest voting histories

[Vice President Christian Man]

Keweenaw County Michigan. Strongly Rep county, became a bellwether in the 1940's, voted for Mondale and is now solidly Rep again.
Burke County ND was a Debs-Wilkie county
Crawford County KS, former bellwether county which went for Debs
There are some Landon-McGovern counties in Massachusetts but that has to do with its brand of social liberalism more than anything else.
Franklin County IN, solidly Dem county until the '30s then solidly Rep from that point on
Sampson County NC was a Dem county before the 4th party system but then became Rep before voting similar to the rest of the South starting in the 1940's. Jimmy Carter was the only Dem to win by double-digits and it trended Dem between 1948-1952.
Hamilton County TN was a Rep-leaning county throughout most of its history that voted for Wallace in '68.
Loving County TX--The only Wallace-Perot county in the country
Polk County NC--Possibly the only Hughes-Cox county in the country. There's one in Michigan but it's disputed as an error.
Charles County MD was the only Dole-Gore county to have not had an urban core and it is now solidly Dem despite it being rural. It was historically Republican as well.
Every McGovern county in Kentucky voted for Trump by a landslide margin and many of them switched to the GOP in the 2000's, some never voting Rep prior. One of them was Elliot County with Trump being the first Rep to win it since 1868.
Riley County KS--Biden became the first Dem to ever win that county.
There's likely others but those are the ones I could think of.