Malt vinegar and hot sauce. Ketchup for the chips. Curry sauce sounds interesting - we don’t have that option in the Irish style pubs that I’ve eaten fish and chips in around the Atlanta metro.
Nice little article on regional preferences for fish and chip condiments, including a map.
Strangely doesn’t mention tartar sauce at all, which I suspect is more common in pubs than takeaway fish and chip places.
It makes sense that tartar sauce wasn’t at all mentioned, given the article you linked to was about chip condiments. (And Brits are weird about chips or french fries. I saw a YouTube video in which a British Asian chef made what looked like a really nice curry and then plated it over chips.)
Ha! Curry half and half! It’s a thing my Welsh wife introduced me to - Indian curry with half rice, half chips. Don’t knock it til you’ve tried it!
(Mind you, this same family served spaghetti bolognese with chips on the side, so I wouldn’t take it has a common activity).
Oh no! Arthur Treacher’s was a big treat when I was a kid. My whole family loved it. Wikipedia says they’re down to 6 locations.
Anyway, most Irish themed bars have fish & chips of varying quality if you want to give it another try. It’s often a special on Fridays. Big & Little’s has a good reputation (I haven’t tried it) and a few locations in Chicago.
We have several of those pubs in the Beverly Hills area, so I just might check them out! 
I’ve seen people sprinkle chips on top of pizzas.
Though the weirdest combo I’ve seen was in Glasgow, Scotland being of the deep fried Pizza, I saw something more than that. Chips. Kebab Meat. Cheese. Basically three types of grease together at last…
Doesn’t sound any worse than greasy natchos!
Dude Food being all the rage in Bristol for some time now, it’s quite common to see ‘dirty fries’ on the menu - chips, pulled pork and cheese.
When I worked in a Wetherspoon’s pub it was a reguar option to have the curry with chips instead of rice. One curry night disaster struck as the kitchen found they had run out of rice. The bar staff were supposed to tell the customers they could still order curry but it would be served with chips instead, but most did not get the message and much complaining ensued.
Wetherspoon’s curries are far from nice, though.
To answer the original question: salt and vinegar on both, ketchup and/or curry sauce on the chips. Cheesy chips is good after a night out ( 
) and I like tartar sauce in restaurants, but it’s never occurred to me to buy some to have at home.
I don’t think I’ve ever purchased tartar sauce. Some mayo, relish, mustard, lemon juice, and capers and you’ve got tartar sauce.
That sounds like a lot of effort for a takeaway fish and chips. But maybe I could try it once. What’s relish, exactly?
The relish Americans put on hotdogs is a minced pickle relish, although you could go all out and make your own relish (and mayonnaise as well).
I don’t trust any recipe that doesn’t know how to spell the thing they are making! As for store-bought, Waterfront Bistro makes a good tartar sauce, as does my local grocery chain (Stater Bros.)
Commonwealth spelling, but I’m sure you know that. It’s a fine recipe and pretty much exactly as I make mine, although I usually use green onions in lieu of shallots, as I more typically have them around (though I sometimes do have shallots around.)
My own recipe uses a mix of mayo and Miracle Whip, with relish, onion powder, garlic powder, lemon juice and capers if I have any. Also a touch of parsley if I’ve been to the store recently.
It can be simpler than that. I just chop up whatever pickles I have on hand, mix with mayo. If you have lemon juice a splash of that, or some pickle juice. Best if if has time to sit.
It has to be salt, vinegar and decent ketchup
AKA Heinz. Because Hunts is for oh no you don’t!
Ha-ha. Nope, All Gold… it’s a South African Ketchup, you should try it. It’s awesome!