Determining what's the best movie ending is a purely subjective thing. No two people will ever agree totally. But, it's been my experience that movies with more realistic endings are the best, for me. You'll see those types of endings in more Independent movies than the mainstream. Sideways, Million Dollar Baby and Pulp Fiction are just two movies that fit into that category. I believe that other movies are considered great because of the emotional range they explore, and then others because of the strong ability of the actors to pull you into a world that you can touch and taste.