Pineapple on pizza. Pineapple is a fruit and a proper one at that, not like that poser tomato. Why the heck would you want it on a pizza?! I just cannot comprehend it. I love pineapple, but when people start having it with savoury stuff it hurts my head. That goes for any fruit too really, but pineapple on pizza (and with cheese at parties, and on gammon steaks and the like) really bothers me.
Oh, and ketchup. Bleh. Salt on my chips and that'll do, thanks. Occasional desire for BBQ sauce, but that's very rare.