This is easy. There is one song that whenever I hear it will instantly make me smile. That song my friends is the smooth stylings of The Friendly Indians singing I Know You Know
Do I really have to explain this? Psych is a HI-LARIOUS tv show. And this is the theme song to the show. Its been done with a Christmas theme, in spanish, performed Bollywood style in Hindi, covered by Boyz II Men and Tears for Fears. Its awesome. And I always know that once it plays i can sit down for an hour be prepared to relax and laugh.