they used to make a taco pizza which basically consisted of crushed nachos and ground beef at this pizzaria, which was one of my first jobs. i pulled pies. i thought it sounded nasty but it was actually pretty tasty.
taco bell makes a mexican pizza but this one was more homemade tasting.
i too never had fries with mayo before going to amsterdam, there were stands all over selling them in a cone. now i cant eat fries with anything but mayo, i prefer it much more over ketchup. i also like salt and vinager with my fries. ketchup is a distant 3rd when it comes to toppings id have with my fries.