He would watch Lego Ninjago, Captain Underpants or Where's Wally ad nauseam. Also some quite young series with DD (e.g. Octonauts). He does have SEN and is quite socially immature.
So far I've got him to like The Inbestigators and Merlin, we like various films but really looking for a series.
He didn't like Dengineers, he'll watch the odd bit of Blue Peter and we have a regular Newsround slot but a lot of other things have not been popular (with one or other of us).