None of them is easy to clean.

Cretors and Gold Medal make the best machines. A 4 oz. or 6 oz. model is probably fine for home use. Make sure that you get one with a heated deck (to keep the popcorn warm and crispy). The pre-packaged popcorn/oil/salt packs (from Weaver or Gold Medal) are probably the easiest way to make the corn. Otherwise, you will need to order corn, coconut oil, and Flavacol separately.

Can anyone recommend a theater style popcorn maker? Looking for one that makes good popcorn and is easy to clean.
We usually have five people watching movies at any one time.