Make your own microwave popcorn at home. It is much cheaper and you will know all of the ingredients. Nothing bad for you here.
⅓ c. popping corn
salt, to taste
melted butter, if desired
Pour popping corn into a brown paper lunch sized bag.
Fold end of bag over, and tape shut.
Place in microwave; lay bag flat. Microwave about 2 minutes, depending on your microwave. Stop once there are approximately 5 seconds between pops.
Transfer to a bowl and sprinkle with salt. Drizzle with some melted butter, if desired.