My bogan secret? I watch Glee every week and I like it.
EDIT: I was going more along the lines of a Hamish and Andy segment they had on once, where a bogan secret is something embarrassing which would be detrimental to your bogan image (Sorry that's as best as I can explain it

For example, a big burly bloke who is a construction worker and drives a ute, could secretly like pedicures. That's his bogan secret