For all the Monty Python songs here. I am a Monty Python fan myself, but I find their songs mostly funny instead of silly.
The first thing that comes to mind for me, when talking about silly songs is punky's dilemma
Wish I was a Kellogg's Cornflake
Floatin' in my bowl takin' movies,
Relaxin' awhile, livin' in style,
Talkin' to a raisin who 'casion'ly plays L.A.,
Casually glancing at his toupee.
Wish I was an English muffin
'Bout to make the most out of a toaster.
I'd ease myself down,
Comin' up brown