I’ll go with:

• Either defining or subverting a genre.
• At least one likeable character, ideally the protagonist.
• Some kind of mystery at their heart.
• Leave you thinking about them after they’ve finished
• Believable characters, convincing dialogue, plausible villain

Way back in the 80s I knew a guy who scored all films by adding up the number of bare breasts and explosions. He said 3 was a minimum score for a good film.