I’ve never tried regular vinegar on fries but I keep a bottle of malt vinegar on hand in case I end up with some fries.
Yummy! I tried it first at The Chip Shop.* I used to live 4 blocks away from it-- man, I loved that neighborhood.
I’ve got a friend who dips his fries in mayo. Now that’s disgusting.
*That site needs to make the ‘turn off that bloody music!’ clicky thing much bigger.
What’s white vinegar? 
And yes. Vinegar all the way in Canada, except maybe on fast food McFries: then it’s ketchup.
Ranch.
Malt vinegar on fries is awesome. Regular vinegar on fries is not so much. Salt and vinegar potato chips/crisps are often barely edible.
Basalmic vinegar on fries is even more awesome.
ETA: Mayonnaise on fries is fabulous, especially with a little mustard mixed in for taste!!! 
Or blue cheese.
Delicious. Although, I must say, it is only fair to point out that my love of vinegar is abnormal, and I have a total vinegar crutch when it comes to cooking. Sometimes while making dinner, in my effort to become a better cook (one of my goals lately), I tell myself “No vinegar,” and about 50% of the time cave in, “Okay, maybe just a little.” When I don’t use vinegar, I often use lime. I dunno, I like things to be tart, I guess.
Unbelievably good. Deep fried + vinegar is almost always a great combination. Usually, for me, it’s deep-fried foods with something pickled on the side, but with fries (and fish) especially, it works great to mix it all into one.
We go both ways.
I don’t like ketchup on my fries. Preferred toppings are:
- brown gravy & cheese curds (i.e. poutine)
- malt vinegar & salt
- any combination of chili and/or cheese
- just salt
I’ve seen olive oil and balsamic used as a bread dip in many, many restaurants. I prefer just the olive oil with some salt and pepper, but it’s good with the vinegar, as well.
Cider vinegar added to deviled eggs makes the dish.
Malt vinegar on fish and chips is terrific, but I do prefer mayo with my fries.
I used to only eat my fries one of two ways: with vinegar (malt > apple cider > red wine > all others) or as poutine. I’ve recently fallen back in love with HP sauce (you Americans have no idea what you’re missing - don’t let anyone say “it’s just like A1” because they’re fucking liars) and now only eat my fries one of three ways. Note: All three of these ways get me strange, strange looks here in America.
ETA: My wife eats her fries with Ketchup and Mayo - yes, at the same time. :boggle:
This is known as “fry sauce” in Idaho and thereabouts.
HP sauce is awesome. I use that whenever I’m at a restaurant that carries it. Usually here in the US, that means an English-themed place, maybe an Irish one.
Malt vinegar, salt, and a little bit of mayo - real mayo, not miracle whip or anything out of a jar.
I do have to say that I’m partial to thin frites served with aioli.
If you’re going to the (rather minimal) trouble of making mayo, you’ve opened the door to lots of fun variants – remoulade, aioli, rouille, homemade ranch.
Malt vinegar all the way. It used to be that the only places that had malt vinegar on the tables were fish & chip places (including the fast food variety: Long John Silver’s, Arthur Treacher (miss it SO MUCH)) but we recently started getting Five Guys around here and they have malt vinegar on the condiment counter. Mmmmmmmmmmmmm…
Another vote for “vinegar, especially malt vinegar, on fries is yummy.”
What an odd thing to get worked up about. Does your stepfather eat ketchup on his fries? Ketchup is basically sweet tomato vinegar.
Vinegar yes, but salt is also a must with the vinegar. No problem, not “putrid”; comes from the fact that fish and chips were also vinegared and salted and served together.
Fries and gravy are quite common here in Canada and always have been. The poutine thing actually dates from the early 70s I believe and was “Quebec only” until about 10 years ago, thanks to chain restaurants.
Chili/cheese are American and are quite common these days.
Mayonnaise is a Belgian thing and I remember reading about it back in the 60s even, so it’s really nothing new. I also use McChicken sauce from McDonald’s, as well as any of the dipping sauces used in Chicken McNuggets, especially the Sweet n’ Sour.