Prawn or chicken on a Hawaiian works really well, though recently I've been ordering BBQ chicken pizzas occasionally since I've realised they are not all sickly sweet like the Dominos ones I ate once as a kid. Other than those I also really like the "gourmet" vegetarian a lot of places do with eggplant, artichoke, sundried tomato, etc.
At home, pizza is just a clearance meal where we dump all the leftovers on it, though we usually have a bunch of frozen pizza ingredients saved up for this. I also love mushroom on any pizza so I always go and buy some if we're making them.