I didn't know anyhting about this until just now.
My doughnut opinions:
Oh, I like those creme filled donuts from KK's and their French Cruelers.
Has anyone noticed that for the last couple of years now that KK donuts smell like that gas the dentist uses to make you feel lightheaded and numb during paticularly painful dental proceedures? Oh well, flavor is still the same.
Dunkin Doughnuts tends to have the better frosted doughtnuts, but I haven't had one in over a year because they went out of site on their prices.
For powdered sugar doughnuts I like those "Sweet Sixteen" sloganed ones, for which I do not recall the branding, Merita's perhaps?. Entemanns has the best chocolate covered cake doughnuts.
Winn-Dixie use to have excellent glazed varities of doughnuts before they went out of business some years back, but it seems like Ingles may have bough or figured out a similar recipe as theirs on right on par. Publix makes a good bulgarian cream filled and decent glazed doughnuts. Bi-Lo use to make great plain glazed doughnuts before partnering with KK to provide doughnuts to their deli-bakery department.
Not a doughnut, but worth mentioning. Some odd-ball grocery store named "The Fresh Market" makes fantasic Glazed Honey Pecan Cinnamon Buns.