Meat and lots of it, some onion and roasted peppers.
I don't particularly mind pineapple on a pizza, something I do mind though and I don't know if you have this in the US is Barbecue sauce used instead of the regular tomato sauce. It has to be one of the most awful thing to put on a pizza ever - but one of the large Pizza chains still continues to sell it. I mean, I could see drizzling a bit over (although I'd never do such a thing) the top, but replacing the tomato sauce entirely? Urgh ... :crash: