One of my favorites is BBQ. Also like pineapple one -- just to start a debate here
I may have to try pineapple on pizza someday. what other topping do you pick with pineapple?
I'd generally suggest keeping it simple - ham and pineapple (on the standard cheese + tomato base). Though I've often tagged the pineapple with meatballs and/or pepperoni, depends on the pizza house as to whether I like their pepperoni or not.