After seeing what some idiot said to Cinzia in a review, here is another question for you.
What is the worst thing someone has said to you in a review about one of your stories?
I can't remember ever getting a truly "bad" review. I've never been flamed, as far as I can remember. I have definitely gotten reviews from readers who were upset with the direction the story was going or didn't like one of the characters, but I can't complain about those because they were honest, for one, and they were from people who were still enjoying the story enough to continue reading and giving feedback. Like a lot of you have said, those reviews show that people are passionate about what they're reading!
I have also gotten nitpicky reviews, like Julilly mentioned, that point out inaccuracies instead of commenting on the story itself, and those can be annoying, but they can also be helpful if they're right. When I was writing Broken, there was a girl who would email me regularly with feedback, and she was a med student, so she liked to give suggestions and correct my mistakes. At the time, it annoyed me because I was doing the absolute best I could to be realistic, and it was disheartening to be told otherwise, but I realize now that 1) she probably just wanted to show off what she'd learned and thought she was being helpful, and 2) she was right about most things, so it WAS helpful, whether I wanted to take her advice or not. I think being critiqued that way by someone who knew what they were talking about made me more of a stickler about doing research so that there wouldn't be any inaccuracies for people to point out. Not that my writing is factually perfect now, because I'm sure it's not, but I did not get nitpicky reviews like that for Curtain Call because I made sure not to write anything without looking it up first LOL.
I guess that shows the difference between constructive criticism and flames. At least you can learn from the concrit!