One's with bloody good chorus's are the best if you want audience participation.
Sea Shanty's allways go down well.
Take a look at the repertoire's of people who you like.
It is easier to learn songs which you like, not one's which other people like, most of the so called standards have been done to death anyhow, create your own niche.
Or, just learn the chorus parts and you can join in with anybody.
Whatever you do, just keep on doing it.
Good luck, JohnB.