Isn't that all of them?
Well, most champs have at least one skill containing a slow or stun, true. But I rather mean a champ focused on cc. Leona is all about stunning and locking up your targets. Caitlyn has a trap and a slow, but they are not completely reliable (it's rather easy to walk around her trap) and you want your Caitlyn to focus on doing damage and not trapping your enemies.
That being said, a few weeks ago Nunu and Galio were freetoplay, and those two ultis are a combination you can hardly do anything against XD Lost all games when I had those two in the enemy team.