DC Comics' most powerful sorceress leads a dual life. She doesn't have a secret identity so much as a civilian life where she performs stage magic for audiences. Her other life is spent fighting crime and protecting people from dark magical forces. Her powerful incantations are spoken backwards and until television versions started appearing, you had to imagine what it sounded like.
Throughout her superheroic career, she has changed costumes many times, but ultimately has returned to her magician garb complete with fishnets and top hat. It was with this outfit that she premiered on television with in the early 90's on the Batman: The Animated Series. She has continued to appear in animated form in shows like the webseries Gotham Girls or the newer show Batman: The Brave and the Bold. It is the classic Bruce Timm style that she's appeared in most often that I like best.
Her costume is an easy one to duplicate for cosplay at comic book conventions and that was the only way you could see a live action version of Zatanna. At least that was the case until Spring of 2009. Zatanna appeared in an eighth season episode of Smallville played by an actress with a magical sounding name herself, Serinda Swan.
She came back in the ninth season and hopefully will make another appearance in the tenth.
I guess we'll just have to wait and see.