Happy Happy Game Show by Kevin MacLeod
Okay, it is a 12 bar blues, but you got to stick around at least until the horns! I couldn't start with the horns as that would be a frightening level of happy. The uncompressed download also comes with a perfectly loopable track for those who don't want the party to end. You can download this in uncompressed format here. Download comes with individual tracks so you can make your own mixes.