To play and sing with other musicians who come from different musical communities,
To hear performers I love and possibly learn about new ones
To dance my feet off if given the chance,
To get away from home and have someone else cook (no camp cooking for me)
To be around a generally happy, civil bunch of people and have a good time.
Sort of what everyone else said, but do I really have to choose the most important aspect? (whine whine)