Favourite? Of currently running series there's Transformers: Prime and Avengers: Earth's Mightiest Heroes. Non-Running series is a much longer list. Least favourite? Eh, I dunno. My brother watches some strange shows on ABC3, but if I don't like something, I don't watch.
I am teh Queen of teh first post!
And I say Batman: The Animated Series.
A fine choice indeed.
Myself, I'm rather fond of Heavy Metal, and the old Transformers series.
I've never seen the original. I've seen the FAKK 2 bit, and I thought it was some of the worst stuff I've ever laid eyes on. If I had to go with something a little more out of the way, I think I'd pick Aeon Flux. I rather liked the first few sets of episodes, where she just kept dying. It had a very raw style. Oooo, or "Le Moin et le Poisson." Technically it's a just a ten minute short, but it's hilarious.
I know you may think this is whack, But I love Regular Show and Adventure Time. I fell in love with those shows ! Mhm, don't laugh.