I really think Jojo`s Bizzare Adventure would be a good fit both for something Jeff and Dan would enjoy (especially Dan) and for them doing a show about it. It has a really good mix of dumb comedy and cool action that would make it a fun topic to discuss.
As others have said finding a thirty second long clip that can work without knowledge of the world or characters and that contains both the setup and the payoff is pretty much impossible, so this might end up just being a clip show of weird gags. Which could be funny, but not really a great way to see whether or not you would want to watch an anime.
Is there any Jojo clip that could convince them to watch it?
Jotaro beating up Dan of Steel and writing him a receipt is pretty great, but I think Jotaro Punches him for more than thirty seconds so you would have to start the clip in the middle of the beatdown which would probably ruin it a bit.
It would be a spoiler for the en of Part 3. but Dio throwing a road roller on Jotaro could also be a fun clip.