I think this is mostly a personal thing, though some elements are universal. Something has to draw you into the story, whether it's action or a character. I respond mostly on an emotional level. How much do I want to hang out with these characters? How much do I care about what's happening in their world? I rarely give out 5 stars ratings, but when I do, it's because a book has the elements of an amazing story, which is: characters to root for, good writing that doesn't distract me with errors or poor word choices, a conflict keeping me awake at night wondering how they'll come out of it, an emotional reaction that makes me think about the story all day and long for it like I long for coffee in the morning. It's this sense that nothing is right in the world until I know that Katniss will make it out of the arena alive (or whatever applies to that story).
Beyond that, it's personal. Some people love mysteries, some people hate them. Any book out there that's being read will have both 1-star reviews from people who think it's compete rubbish and 5-star reviews from people who think the author is a god who delivered an eternal holy relic upon the earth. I think mostly, though, we love or hate something based on how it makes us feel. And a good story is one that makes you feel something.