un H A P P Y?

I'm H-A-P-P-Y,
I'm H-A-P-P-Y,
I know I am, I'm sure I am,
I'm H-A-P-P-Y

…and was the theme tune to the sitcom “Only When I Laugh” which starred Peter Bowles, James Bolam and Richard Wilson.

More details here: http://www.phill.co.uk/comedy/laugh/