My husband and I use a Black & Decker convection toaster oven that can fit at 12" frozen pizza in it and has bake, broil, toast, and keep warm modes. We got it at Target for less than $50 I think. It's been awesome and we've saved a ton of natural gas and money with it.
Our apartment's oven has such terrible insulation that baking something in it would make the AC kick on. Now we use the toaster oven exclusively in the summertime to bake and broil things. I've done enchiladas, tofu lasagna, cookies, brownies, and homemade pizza in it, in addition to the frozen pizzas. I recommend an 8X8 pan for the lasagna and brownies-type baking.
Highly recommend!
PS- For baking things with cheese on top, like the enchiladas and lasagna, I place foil over the top for the majority of the cook time to prevent overbrowning from the top heating element, then remove for the last 5 minutes to get a nice golden brown.
PPS- Only type of frozen pizza you can't do in the toaster oven are the type that require it to be on a baking sheet. So read the pizza instructions before you buy (only when on sale!) and choose the ones that say to place directly on oven rack.