My experience says: celebrity, carnival, norweigan but all three were very good! Celebrity's is slightly more upscale. Although I like to think of myself as at least a little sophisticated, sometimes I didn't know what items were and would have to ask the waiter. Also, they have truly fabulous homemade deserts, breads pastries and ice cream. By comparison, on Carnival I found these types of items only passable - I wouldn't bother with them reasoning that I'd rather have the yummier items take up space in my tummy and add to my calorie count!
I have had better food at very expensive restaurants (the truly extraordinary ones) but each of these lines offered fare that was as good as most expensive restaurants.
You will not go hungry.