I guess what I enjoy most is directing, because it incorporates all aspects of filmmaking. Directing is in the same line as acting - both are popularity contests, and in both you're trying to tell a story through the film as a medium.
There's a tendency, when you're directing yourself, not to give the performance as much care, because you feel like there's too much focus on yourself, or that all these people are just standing around setting everything up, waiting for you.