Basically I think you want some type of countertop convection oven or toaster oven big enough to handle a decent sized pizza. You want it to go to 500F or 550F, the hotter the better, because it's best to bake pizzas at the highest temperature possible. I think you also want to get one that is at least 1000 watts, so it reheats quickly after you close the door. You can make some awesome 12-14" pizzas in a good countertop oven.

On the other hand, if counter space or $ is an issue, this thing gets good reviews. It's used primarily by people who eat lots of frozen pizzas, but it also works on fresh pizzas.

If you eat frozen pizza I would suggest a pizza pizzaz. It's so much faster than preheating an oven!

Presto 03430 Pizzazz Plus Rotating Oven https://www.amazon.com/dp/B00005IBXJ/ref=cm_sw_r_awd_K3uVvb2S33FVT