The last funny one I worked up was "If My Nose Was Runnin' Money".

Chorus:
If my nose was runnin' money, I'd blow it all on you
I'd buy you a Cadillac, a new Mercedes too
I'd build you a mansion up on that mountaintop
If my nose was running money, but honey, it's not

I also liked Lyle Lovett's "Keep It In The Pantry".