Werewolf vs. Ancient Dragon. So much fun, I did it twice. Didn't really have a good picture lined up the first time, though. You still absorb their soul, and if there's a Word Wall nearby (like there was here), you can get that. Can't open chests or search the dragon, though.
Oh, I had all my werewolf perks, and he went down after 3-4 hits. He barely scratched me, as you can see. And I'm level 55, if that matters.