I seems the important questions are being ignored in the Trump thread, so its time to finally have a thread about this.
Pineapple is OK on pizza.
There, I said it. Its OK on pizza. Whats NOT OK on pizza is so many toppings that everything becomes a homologous tasteless wasteland of goop. Pick your toppings wisely so that they combine in to something with flavour and yet are still detectable as individual ingredient, and yes, cheese counts as a topping. Cheese is NOT just glue to hold the whole thing together. Pick a good cheese. A tasty cheese. A cheese that complements the other flavours.
The other things that's not OK (even with the abomination that is a stuffed crust) is eating a pizza crust first. I will even allow that some people feel the need to eat a pizza with a knife and fork like the retarded children with no motor skills they are, as long as its not crust first.