What on earth? My favourite episode of a show is Batgirl's premier? It's sad but true. Though batgirl is totally annoying as usual, Poison Ivy is totally awesome. Pierra Coppola (sp) is a great voice-actress and really captured Poison Ivy's essence well. And except for the fact that he was a silly villain, Jim Cummings does the voice of Trembler, and well-- everyone loves Jim Cummings.
Though I didn't like the Pamela Isley all that much. Haha, I'm really hoping they introduce Harley now, though. I mean, Harley is owned by DC comics now, right? Using her in the show would be fine, I think. (I honestly just want to see Harley and Ivy team up. xP)
Overall, an excellent piece of work. Teenage Ivy is a stupid idea (considering she even acted like an adult...), Batgirl is always annoying, and Jim Cummings and Piera Coppola were both well casted.