Here's why I want to know: enough of us are bummed out constantly, over one thing or another. It's just the way our lives go. So I figure, if we can put together kind of a database of happy things and why they make people happy, then when someone's feeling down, they can always look through the list and say "hey, that helped so-and-so through something like this; maybe I'll give it a try, too!" At the least, it'll remind us that we do have some happy moments in our lives!

Here are three that I can think of, off the top of my head:
Riding Motorcycle
It feels like running away from the world. Nobody can talk to me, but they all know I'm there. It's a different world for me. I ride a little faster and harder, throw caution to the wind a little more, and take one more step away of normal society. I may want to be accepted by (some of) them, but I don't want to be one of them.
Photography
I've only recently started doing anything serious, but I'm already loving it. It's a chance to capture moments that just make me say "wow." Some are funny, some are unique, but all of them (the ones I keep, anyway) say something. It's almost like getting to create beauty, even though you're really just capturing it. It makes me feel like I'm a part of the world without having to actively interact with it.
Helping Here
Yeah, seriously. Especially since becoming a mod, I've done things that I NEVER, in my wildest dreams, expected to be doing. It's scary, but it's exhilarating at the same time. More importantly, when someone is going through a crisis and I can help bring them back from the edge, it gives me that sense that I've done some good to someone in the world, that I'm not as useless and unneeded as I often believe I am. Ask Ali; she knows all about my craving for feedback. So yeah, being on here and helping people, even when I'm going through my own things, makes me feel better.
So those are mine. What's yours?