I always viewed grits as being made from hominy while polenta is made from untreated yellow corn. Hominy is more nutritionally complete so it was a better choice as a staple for poor people. You lose that fresh corn flavor but gain riboflavin (or something like that).
Simple grits with butter and salt topped with a perfectly cooked over easy egg and a couple of sausage patties is my go-to comfort dish.
Shrimp and grits is my next favorite way to eat grits. I like them with a creole sauce (made with dark roux, cream and a shrimp shell stock) and andouille…no cheese. Fine dining that.