On top of Old Smoky and/or spaghetti, mainly the verses about shooting Castro and Khrushchev with polychromatic rubber bands.

Rolling home (I've got sixpence)

PP&M/Pete Seeger civil rights era standards

Tom Lehrer standards

The Burning of the School (it's somewhere on my website)

Bill Grogan's goat

My name is Macnamara, I'm the leader of the band

The Deitsch Company

There was a goat named William

Seresponda - O Nicodemo

The Fox went out on a chilly night

Hymns

Pretty much the same sort of stuff I still sing, though until I was 16 none of it was in Esperanto.

Liland