What do you use TTS for?

When we think about improving TTS voice quality, we always need to consider the scenerio that TTS are used in.
For example, if the scenerio is accessiblity, TTS needs to be highly intelligible in all conditions.
If the scenerio is reading turn by turn directions, the key information of routing needs to be highlighted and more prominent.

So if you are developing or have an application that uses TTS now, what do you use it for? What kind of expectation do you have on the TTS quality?