If your always at the gym and live off of diet drinks and protein shakes, you'll love smoothie king. Otherwise, you can make a much better smoothie at home. I used to get smoothies at the Bally's on Kendall Drive and 107ave, but once they shut down the juice bar, I haven't found a comparable smoothie. South Beach smoothies behind the Bally's was good as well, but I don't know if they are still around.
Pros: Friendly service
Cons: No natural fruits, nothing natural at all actually