Basking in the sun in a vast, spacious, grassy field in the middle of spring on a only slightly cloudy day is one of the greatest of feelings in the world to me. The feeling of the suns rays kissing my cheek... the sensation of the grass on my back and my legs... the scent of the plant life around me.... Pure. Bliss. Emotionally, I'd say that people coming to me for help with anything (particularly computer problems). It makes me feel like I'm important for something, which is an emotion that I seem to lack most of the time...
Pony related: When someone says they like something I made or find find something I like. Non-pony related: When I get to drive on a track in something designed to do just that, I just love it.