I have to disagree about using a microwave on pizza; it is all in how you use it. Full power screws up the pizza 98% of the time. To "take the frost off" of leftover pizza, use 60-70% power for 90-120 seconds. If the crust has gotten hard, this can soften it up and warm it just a touch. Since each micro works a little differently, reheating pizza will require a little experimentation.
I have to disagree about using a microwave on pizza; it is all in how you use it. Full power screws up the pizza 98% of the time. To "take the frost off" of leftover pizza, use 60-70% power for 90-120 seconds. If the crust has gotten hard, this can soften it up and warm it just a touch. Since each micro works a little differently, reheating pizza will require a little experimentation.