I've been seeing and talking about movies my whole life. I have recently come up with three simple criteria (or pillars) that make a movie or tv show "good"! Each of these pillars will be introduced below, along with some examples of movies or shows that did well or poorly in those areas.
1) Character Development: This is a broad term, but simply, it falls on the screen writer (as well as the director and actors to a lesser extent) to make the audience invested in the success or failure of the characters. More specifically, the audience needs to root or cheer for the protagonist of the story. Along the same lines, the antagonist needs to be feared, despised, and understood - as the antagonist is the hero in his/her own story.
Protagonist(*), or the leading character, does not necessarily need to be the moral compass of that universe. In the golden age of TV, most protagonists are sometimes antiheroes (e.g., Tony Soprano, Breaking Bad's Walther White, Mad Men's Don Draper, the Punisher). Despite the flaws, audience still wants to see the protagonist succeed. As example of a show that failed in that regard, I can think of Boardwalk Empire. That show was created by Terence Winter (a Sopranos alumnus) and produced by the great Martin Scorsese. The sets and calibre of actors were top-notch, but I couldn't care about any of the characters - neither the intended protagonists, nor the antagonists.
The product needs to invoke the right feelings in the audience.
2) Story Logic: It's an unpleasant feeling when after the movie or show is over, you can think of something that could've ended the story 10 minutes in. This is not always a deal breaker though. One example that comes to my mind is Lord of the Rings trilogy. It has been a question for me (and countless others I assume) that why Gandalf didn't ask the great eagles to give Frodo a ride to mount doom. The eagles could have at least shortened the journey by a great deal. As a result, we wouldn't have nearly 10 hours of movies. Or in many superhero films, maybe the main character could've used a certain power and finished the job right at the get go (e.g., Superman could use his heat vision to incapacitate enemies instantly, as that laser beam supposedly travels at the speed of light. Instead he stands and looks helplessly).
I consider this a lesser sin, because the ride might be fun enough that you could forgive those mistakes. Lord of the Rings is a fantastic trilogy, and I'm happy that we have 10 hours of it, rather than just one hour.
As an unforgivable example, I can think of Ocean's 12. We see in the last 10 minutes of the movie that it was all a ruse, and even the team (Danny Ocean and co.) in their own private circle, acted as if they were a few steps behind. Why would they do that? They needed to play coy in presence of others, but why in private?
The audience appreciates a tight and logical story line.
3) Pacing: One of the major reasons for watching movies and TV for me is escapism. I'd like to lose a few hours in a world that is different from my own routine, and get immersed in a different story line. For me, a movie or TV show succeeds in this regard if I don't look at my watch while I'm watching it. The Marvel movies are prime examples that make you lose track of time. In a blink of an eye, the movie is over, and you are happy for spending time with those characters.
Some of the art-house or independent movies, regardless of how interesting the story is or how advanced the acting might be, make you feel that the time has stopped. Revenant, some of the movies that Martin Scorsese makes (e.g., Raging Bull, Mean Streets, Gangs of New York), and most of the European or foreign language films that get nominated for Oscars, are example of movies with horrible pacing.
A well-paced movie makes you lose track of time.
Wrap-up: Ideally, an entertainment product should excel in all three aspects of character development, story logic, and pacing. Of the three, however, the only one that can sometimes be forgiven is logic, as long as the ride is entertaining.
To demonstrate this point, I would like to refer to Stagecoach (1939), a classic in the Western genre, directed by the legendary John Ford - the record holder for four academy awards for best director. At the climax of the movie, a large group of Apache horse riders chase after the stagecoach that is driven by the cowboys (a classic cowboys and Indians chase). The scene last for over 10 minutes and is full of thrilling stunts. Some moviegoers asked why the Apache didn't target the horses carrying the stagecoach to win? John Ford's response was: "because that would've been the end of the movie".
I happily ignore that logical lapse, as I am pleased to have watched that epic chase scene!
(*) I also have written a post about what makes a "good" protagonist in my opinion.