My kids like any animation like Star Wars Clone Wars, Ben 10 and my TAS DVDs.
My 9 year old watches TOS I think to be with me and because I have some of the toys like the Mugatu and the Gorn and Khhhhaaaaannnn.
He watches the TOS movies with me. I thought he'd be scared by the worm thing in the ear in TWOK but he tells me its not a real worm - its only a movie Mum. He's more scared by reality TV than by any movies. The Hobbit movie was too long for him.
He really doesn't have the patience for any other TV series except he used to watch Cleopatra 2525? with me when he was 5 or something