The definition of pizza is wide open, and it's okay to break the rules to create new, surprising, and unlikely flavor combinations.
Chris and I have very different pizza interests. Where he is a diehard for simple pizzas done to perfection, I'm looking to be surprised and try interesting, worldly, and unique flavor combinations. When I look at the menu, I'm the guy who orders the pizza with grapes, goat cheese, cashews, or crab meat. Pizza crust is the perfect blank canvas to combine different flavors, it's an edible painter's palette and a stage to try new things.
Okay that's all very romantic and esoteric, and maybe I just like to think of myself as creative and edgy. The practical test when I think about my all time favorite and most memorable pizzas - they've all been specialty and even award winning pies. They leave an impression, and it's something more than "wow that hit the spot," they leave me thinking "I had no idea you could combine those ingredients!"
More recently I'm realizing that I like to have pops of flavor instead of one uniform taste. Or, if the flavor is uniform, I at least like to taste the individual ingredients in waves. When I bite into a slice, I want to be able to notice the ingredients from start to finish. Whether that's a fresh jalapeno to wake me up, a big hunk of smoked sausage, or medallion of goat cheese - I need these landmarks to keep things interesting. At the same time, the ingredients should all come together to create an overall impression. Being able to taste individual ingredients taken to the extreme basically turns into a charcuterie board - and I don't want a de-constructed pizza, I want a pizza.
I'm realizing this makes me sound super snobby and like I have impossibly high standards. You should see what I eat when I'm not having pizza. I'm fairly indiscriminate. Lunch is a can of soup poured over rice. Dinner could be tuna nachos with cottage cheese on top. I really am not what you would consider a sophisticated foodie. Maybe that's why I like complex flavors when I'm eating out. Getting pizza is a treat and I want to be taken on a wild ride.