When everything is going right!
A good nights sleep.
Drugs? :P Actually stepping through the gates of Disneyland for me for the first time per trip. It's like oooo all mine ALL MINEE!!! MUAHAHAHA!!
Oh and also when You're enjoying your derby game so much you start dancing in your skates and it gets your friends/teamates to do it too and soon everyone who's lined up is doing it.
When your newborn baby squeezes your finger and looks into your eyes for the first time. It's so beautiful and pure it's like meeting God.