I typically do not eat fried food at festivals or most restaurants. If they are frying any shellfish, I can't, unless they guarantee separate fryers (and most share fryers.) The only time I've had fried dough since I was a child (developed shellfish allergy as a teen) was at Farm Aid many years ago, when they were serving a multigrain fried dough with flax seeds, and not frying anything else.
A few people mentioned the Big E above, which was the big fair of my childhood (also had a few smaller local ones; I grew up about 25 minutes from the Big E grounds.) I don't think I've ever had anything fried there; I think I have always gone for the state-specific treats in the state buildings and not the more typical fair food outside. Why is it that a baked potato from the Maine building feels like such a treat even though I grew up in a potato family?!? My regular, smaller fair food was always a snow cone as a kid.
The town I currently live in is like a fair every night and all weekend during the summer, with rides and fried food stands. There's one stand that just sells fries, so I can eat those (and they're really good, so I try to stay away.)