Great idea for a thread by the way.
Vinegar HAS to go on my chips. No vinegar means no chips for me. I was always the only one out of my friends who lothed going to McDonalds - not selling vinegar for chips is disgraceful in my opinion, but there we go - it has provided me with a lifelong reason to avoid McDonalds like the plague, so I shall not complain too much
As for sauces in the strictest sense...
Curry sauce and chips is my all-time favourite - saturday night treat.
I very rarely have chips now but as a kid, tomato ketchup was a favourite - I loathe it on chips now.
So... BBQ sauce for me - the HP one is very yummy, seconded to HP Brown Sauce and third... Heinz Salad Cream - now that is nice!