I called both of my stepparents by their first names. Cinderella calls me by my first name.
My parents she calls Grandma & Grandpop. As does The Boy and [eventually] The Mouse.
My stepmother goes by the name "Nanny" and her mother "Granny".
My stepdad was referred to as "Poppi" (we all called him that, actually).
We use pretty traditional monikers in our family and they are used by ALL of the kids, step and bio.
What kind of labels do you use for/with your "steps"?