Wisconsin resident here.
If we're talking by itself, a real sharp cheddar will almost always be my favorite. It's the old standby that needs no cracker.
I like pepper jack and similar hybrids, but I feel the peppers take up room where there could be
more cheese. Put a jalapeño on top of it or something!
On a sandwich, provolone is king, although Havarti would be a close second.
On pizza, I find a 70-20-10 mix of Mozzarella, Cheddar, and Swiss to be really good.
I can't really deal with "american cheese". Something about it seems....off. Too heavily processed, maybe?
Best Poll Ever, btw.