What would you recommend I eat there?

I don’t think I’ve ever had anything there I didn’t like, but I’ve definitely honed some favorites over the years. A few go-tos of mine:

Double cheeseburger with grilled onions and mushrooms. You can also add lettuce and tomato, but honestly it’s pretty great with just the cheese, meat, grilled onions, and mushrooms. The ratio of flavors is perfect.

Mushroom and Swiss on sourdough with mayo, lettuce, and tomato. This is messy as hell, but it’s delicious.

The Wisconsin Swiss on Rye, but substitute American cheese and have them put thousand island on there for a really good smashburger version of a patty melt.

If you want a salad, whatever seasonal salad they have (cranberry bacon bleu, strawberry fields, etc) should be your go-to. You can substitute crispy chicken instead of grilled if you prefer. Theoretically you can even substitute a burger patty or fish, IIRC.

Their onion rings are unique and I love them. Almost like someone heard of the idea of onion rings, but only had thin burger-sliced onions and simple fryer batter.

Cheese curds are always good, too, but you gotta be hungry. They’re basically just little balls of fat and protein and are very filling.

During lent they may have walleye. I like their walleye more than the cod. Both are good, but I don’t often get fish. Not my thing.

And of course the custard is excellent. If the flavors available (chocolate, vanilla, and flavor of the day) aren’t to your liking, you can basically create whatever you want by adding toppings to a concrete mixer. I’m a big fan of peanut butter cup and banana added to either chocolate or vanilla. You really can’t go wrong though, get whatever custard you think sounds good and it will be good.

My major recommendation on custard is to err on the side of smaller sizes. It’s very caloric. Delicious though.

Pork loin sandwich is good shit

I like to hack together poutine there. They have all the ingredients, but it isn't on the menu.

Double Deluxe with bacon, no mayo, no cheese, side of BBQ sauce and cheddar cheese sauce, dress with the sauce yourself. I don't trust the workers to not make it a gloopy mess.

I prefer Freddy's over Culver's if they're both an option, however.

Culver's puts the AED right next to the soda fountains. They know their customer base, and are concerned about their safety and ability to come back.

If you ask them what a butterburger is they’ll tell you: they generously butter the top of the bun before toasting it. Otherwise they’re just smashburgers, but I think they do a good job with smashburgers. Also custard is delicious.

I think I've ordered a "butter burger" once, they have a lot of other great stuff on the menu.