Given that cheese is a defining characteristic of pizza, anything that calls itself a pizza but doesn't have any cheese on it really has to excel on another defining characteristic of pizza - the toppings - in order to justify its place among the pizza ranks.
In the frozen pizza aisle at the grocery store I found one such cheese-less pizza that compares quite well against its cheese-laden counterparts. Amy's Roasted Vegetable No Cheese Pizza is a tasty pizza that I would seriously consider swapping a slice of traditional pizza for. The roasted vegetable topping has a subtley sweet roasted flavor that creates a nice aroma and is pleasing to the taste buds. I usually pick one of these up for my daughter whenever we want to have a pizza night and inevitably, I will want a slice of her pizza along with my other cheesy slices.
A side note on dairy-free pizzas: You may think that soy cheese pizzas are dairy-free, but I've found that soy cheese pizzas are typically not safe for those suffering from dairy allergies. Soy cheese pizzas often contain the milk protein casein which may not be safe for many people with dairy allergies. So you're better off just getting a no-cheese version like this one. No cheese, no worries.