we used to have Alexander & Hornung beef hot dogs in the Detroit area, until they went bust. Nathan’s and Hebrew National are the closest I’ve ever been able to find.
Portillo’s is a great place to get a baseline Chicago hot dog. Most importantly, they use a natural casing dog, which a most of the ma & pop places in my neighborhood don’t use, which is very disappointing to me, as nothing has quite the snap of a natural casing dog (when prepared properly.) It’s a delicious, dependable Chicago style hot dog, fully dressed to seven ingredient Vienna beef specifications. If you want a benchmark for that type of fully dressed dog, Portillo’s is perfect. I personally prefer my hot dogs with normal relish (not the nuclear green stuff) and sans tomato, and I can live without the poppyseed bun (so, basically a Gene’s and Jude’s or Jimmy’s Red Hot), but when I want to go all the way, Portillo’s scratches that itch. (And then there’s a few places that will even add fresh cukes, lettuce, and even green peppers to your dogs for a true “dragged through the garden” style.)
Not too far from my office is a regionally well-known butcher shop that makes its sausages on premises. They have, according to their website, a “National Grand Champion Beef Wiener” which they sell from a hotdog cart during the summer months and, if there’s one thing better than a well-dressed Chicago dog, it’s a well-dressed Chicago dog that was freshly created. The first time I had one I immediately knew that this was the best hotdog I’d had so far. Even packaged, the dogs from there have ruined me to the store brands.
In 1972, my family (parents, three siblings, and I) took a vacation trip from Ohio to New England. On a rainy afternoon in Rhode Island, we were hungry, and pulled off the highway after seeing that food was available at the exit. What greeted us was a ramshackle stand run by some hippie types and emblazoned with a sign that consisted simply of the word EAT spray-painted on a wooden board.
As it was pouring too hard for my dad to try to drive, we decided to take a chance, and each of us ordered a hot dog and drink, as those were the only items on the menu. The wieners were cooked just right over an open fire, and we were satisfied as we got back into the car. By then, the skies had cleared enough to allow us to see the large restaurant atop the hill just above us!
Just the other day, I had my first “Pronto Pup” at the Minnesota State Fair. I ate it uncondimented; it didn’t need anything.
(Am I from Minnesota? No, but I try to make it to their fair… it’s huge, educational, cultured… and tasty!)
Oh, but emotionally my best dog was at a Milwaukee Braves game with my dad. We yelled at a vendor, who pulled a paintbrush out of a bucket full of dark brown mustard and slathered our hot dogs before handing them over.
Now, I’ve never liked mustard, but being with my dad and a champion team and the good ol’ hot dog guy made it wonderful.
For a really good Pronto Pup, you have to get there early in the morning, when the cooking oil is still fresh. They’re superb then; later in the day, not so much.
The only thing I’d put on a Pronto Pup is mustard, yellow or brown.
Damn, now I want a Pronto Pup! 
The Yankee Doodle Coffee Shop on Broadway in New Haven offered “pigs in blankets:” split franks stuffed with cheese and wrapped in bacon, on a roll. It was one of my favorite nosh stops during my college days, although I usually opted for a couple of (McDonald’s sized) fresh hamburgers. Closed in 2008.
Thumann’s natural casing pork & beef hotdog, on a buttered and grilled top split bun, with good sauerkraut and A. Bauer’s horseradish mustard. Two…
I can’t say I’ve ever had a transcendent hot dog experience. Maybe not liking mustard, hot peppers, and sauerkraut has something to do with that. But
I like the Papaya King Frank with pickle relish, and a side of a virgin Pina colada.
Being hungry helps, too. But I do like hot dogs made on a grill, and allowed to burn just a little.
Lafleurs in Montreal. They were steamed, pale pink franks in a gummy hot dog roll. Tons of yellow mustard, relish and onions. Entirely delicious and unsatisfying at the same time. You could eat 4 of them and still barely feel like you’ve eaten. But yeah, when I think hot dogs to this day, I think Lafleurs in Ville St. Pierre, Montreal.
“Steamies”! It is to hot dogs what White Castles is to hamburgers. (I love the latter, I’m still a little confused about the former, but there is something about them, which is probably how a lot of people feel about WC’s. I can’t remember if it was a Lefleur’s I went to while in Montreal to try the Montreal-style hot dog, but it’s not unlikely that that was the place.)
La… 
Bayville NY, 4th of July. They put on an illegal homegrown fireworks display there every year on the beach, along the rim of a horseshoe shaped bay, fairly wealthy suburbanites blowing $10,000 apiece on some serious incendiaries. Hours and hours of things going FOOOM!!! out of tubes, arcing overhead and going kersplooey in bright colors, with people dancing to music from their radios. Grills everywhere.
A return trip after a few hours of just drinking beers and watching the show, damn I’m hungry, some remaining buns (cool), and grabbed the tongs and retrieved a pair of weiners that had been roasted to the point their casings had popped. Black scorchy stripes from the grill on all sides. Guldens on this one, Grey Poupon on the other, horseradish on both, some jalapeño slices on the first one, raw onions on the other. ETA: oh yeah sauerkraut, the kind that was rinsed and then fried in pork fat, both dogs. /ETA Now that’s an independence day feast!
I’ve never had a hot dog that I can remember as good. The closest is “choripán” with a pork sausage (chorizo*) and ciabatta. Some Peruvian-style mayo and a bit of mustard.
*no to be confused with Spanish chorizo, which is eaten raw. In Latin America, chorizo is coarse-ground pork (sometimes mixed with beef, rarely all-beef) sausage. In Spain, it’s a cold cut.
we’re more likely to find Mexican chorizo in the US, which is very finely ground, very “loose” and fatty and would be hard to eat as a sausage link.
England, although I have had a burger at Mr. Bartley’s in Cambridge, MA
Yesterday I had a Bauenwurst (“farm sausage” — seasoned like a kielbasa but German and fine-ground) from Schaller & Weber on 86th St and Second Ave, Manhattan, roasted and split on a fresh roll and covered in last week’s homemade chili out of the fridge, reheated.
Ooh la la.
As a just married & attending college person I worked at a Pittsburgh institution called Weiner World. Best dog’s I ever had, and free for employees.
The Boston Hot Dog Company in SAlem, MA sells an awesome variety of hot dogs. You can get an idea from the signs in some of these links. They deserve to be better patronized than they are, but they’re a bit off the beaten tourist path (unless you’re going to the Witch Dungeon).
I had a Thai dog that was outstanding there. They also sell veggie dogs
When I was at UNC Greensboro, there was a local hot dog and ice cream joint called Yum Yums. I never had the ice cream but the hot dogs were great. Especially the chili-cheese dogs. Have never forgotten them.