For me, a great story is one where everything that was set up throughout cleanly pays off by the end; logically, thematically and emotionally, and which takes you through a story where the outcome could not have happened without some change or revelation on the protagonist's part.
I tend to judge the success of a story overall on how well it ended. One of the best is "The Girl With All the Gifts", which is a book that's a twist on the zombie formula that just perfectly ties up at the end with a thematic and logical payoff that makes complete sense and also ties so perfectly into the mythological theming that I was left like "how didn't I see that coming!?" It's somewhat underrated, though it did at least get a movie adaptation.
Another great story, to me, is the Scott Pilgrim series (yeah nah the movie is fun but it kinda... misses a lot of the point of the comics). The theme is "growing up", which is a theme we see a lot, like it's a coming of age narrative, but it has a genius twist: The protagonist is an unreliable narrator who is trying to escape from real life growing up by trying to make his life more like a Fantasy coming of age story where growth and success come through collecting items, defeating bosses and "getting the girl" rather than the real stuff growing up involves, like taking emotional responsibility, being at peace with not being at the centre of the universe and understanding that everyone has baggage and relationships are complicated and hard work.