A great comedy movie has the same requirements that make any movie great, but what makes them funny? We'll look at that after first looking at the essentials.
Any movie needs the following; Story, Script, Character and Actors. So how do we upgrade from there? First, let's just add the word 'good' in front of each of those and then throw in Good Editing, Good Camerawork and DOP (Director of Photography), a Good Director and for good measure, lets add a fearless Producer, in those cases where budget starts to look like a problem. Let's assume that, even if we have all our required ingredients, the infinite number of things that can ruin a movie, such as bad make-up and wardrobe, gross blunders in continuity and six months of sudden snowstorms on a tropical island set, are somehow covered by great direction and production teamwork.
What we now need are the magical spices that make a good movie great. There are times when we have all the ingredients but somehow, it just doesn't work. So, you noticed, I used the word 'magical'. Yep! That's what it is, folks, magic. In the same way that you could have two excellent pianists play the same music and one will get applause and the other, a standing ovation. Why? He or she had the magic, that indefinable something - which is why film-making is an Art.
Now a great comedy movie needs the actors to be totally in tune, with a sense of timing that has to come from either a very natural place or be very craftily directed. The editor plays a key role in the timing, too. As any editor worth their salt can tell you, one bad cut can destroy a gag. Even so, any actor can tell you that this is useless without a great script.
So lets look at a word that's being used a lot these days among TV series folk. 'Relatability'. It's not even in the dictionary yet, but then, neither was 'google'. It means that you, the audience, can relate to how the character on-screen is feeling or how they cope with something, or that the mistakes they may make are just the kind of goofs you'd either make yourself or have seen others do, enough for you to think, "Gosh, that is soooo IT."
The character you relate to doesn't even have to be human, but their behavior must invoke a response of recognition in you, thereby making them more human anyway. Whether it's a giant centipede embarrassing itself at a wedding or a guy who looks like your uncle, suffering a hangover - it's all stuff we relate to.
Let's take my favorite movie 'Groundhog Day' as a perfect example of what makes a great comedy movie funny. A great story, a great script, great support actors, the magic spices of that indefinable something and the immaculate timing of Bill Murray, whose facial expressions alone can crack me up and... I CAN RELATE!