Singing
Brian Eno puts this really well - it's a sentiment I've tried and failed to express for a long time.
Singing aloud leaves you with a sense of levity and contentedness. And then there are what I would call "civilizational benefits." When you sing with a group of people, you learn how to subsume yourself into a group consciousness because a capella singing is all about the immersion of the self into the community. That's one of the great feelings -- to stop being me for a little while and to become us. That way lies empathy, the great social virtue.
As someone who spent over 12 years of my life singing each week in a choir, and another 4 years involved with the DOC, in which singing is integral, I can attest to this. There are so few ways to truly become a part of a positive group consciousness; singing is by far one of the best.
(via kottke)