1. Back lit scenes with distracting backgrounds.
I was shooting my daughters 12th birthday party in our outdoor room. The outside of the room was much brighter than inside the room. To help balance the exposure I used a fill flash which is how I have the subjects and background all having the correct exposure. While this may seem to be correct, it really depends on the background. In this case we see a lot of distractions. Since this was a raw file I was able to increase the highlights to overexpose the background on purpose. In the image below you can see how the distractions have been minimized.
2. To correct poor skin
A slightly overexposed image of a person can help minimize skin problems and reduce the amount of retouching needed.
3. At the beach or any time the dynamic range is too great for a proper exposure throughout the entire image. Sometimes for creative reasons you just have to let it go and let the highlights add drama to your image.