Well, yeah. Tomato sauce with tomato paste and some garlic and basil and a bit of olive oil, I think, with a pinch of salt.
Though sometimes we just buy frozen margherita pizzas and just add a ton of toppings before putting it in the oven. I could try to add a bit of ketchup on a piece of it, to see how baked ketchup comes out on a pizza.
To be fair, I tried also to put some sweet and hot asian sauce and it was sort of amazing fun that one time, so who am I to judge!
I'd tried something like that as well!! I like sauce on pizza. It's delicious - especially if it's unusual and tastes exotic. I must admit I'd never eaten a fruit pizza, though. Have you? The only fruit I'd had on my pizza was pineapple...
I also add toppings if I buy frozen pizzas. Somehow it's not enough to just put it in the oven.