What is your favorite subject to teach?

The group I work with recently vamped up some of our classes-changed things around-added a few a la carte options...it was really fun to put together and even more fun to come up with a class outline.  The first class I taught focused on pain coping techniques and partner support.  While I was teaching and watching the class interact with one another and try out different techniques I realized how much I enjoy teaching this subject.  Most couples are quite focused because this is what they are looking for-how are they going to get through this-what do they need to learn-and what do they already know.

What is your favorite subject to teach?