Dannichu
Tragically unbeyachted.
I don't actually like BBT, but Barenaked Ladies (who did the theme song) are possibly my favourite band, and loads of their songs are really happy* and make me grin. If I Had $1000000, Life in a Nutshell and One Week are all fabulous.
*Except the sad ones. Which are just sad. Although some of their sad songs manage to be happy (I'll Be That Girl is so cheerful you forget it's about suicide, and Tonight Is The Night I Fell Asleep At the Wheel - the song subject really is what you think - is set to a waltz).