Honestly something I got for my partner - a silicone microwave popcorn bowl kinda like this one. I stumbled across it at Goodwill, still brand new.

It’s a medium sized, black silicone bowl with a vented cover - fill a recessed space in the bottom with normal popcorn and microwave for a few minutes.

No extra packaging, no grease, easy cleanup, and you can use cheap (or super nice) popcorn as you like. And it collapses down for storage.