In your opinion, what was the hardest Daedric Quest? Personally, I would have to say it would either be Maridia's, or the Clavicus Vile one...

Me, I had OOO operating, it was the Hircine quest. The Unicorn just kept absorbing my health. In the end I got bored and led it to the gate to the Shivering Isles to escape. There it attacked the npc with the drawn sword. I went into SI and forgot about it. When I came out the beast was lying by the gate defunct. I am not sure why but I certainly didn't kill it. Still I got the horn - as it were.

Yeah. I was just at my friends house, playing Oblivion all night on his PS3, and he snuck up on the Unicorn with a Chameleon effect, and then rode it around, and the game considered it as his horse... we ran into a few complications later though. Like whenever he drew his weapon near it, it automatically attacked him! The funny thing was that he wasn't even looking for it!

But the Meridia quest, with the 5 Necromncers, who are all 3 levels above you, when you're at level 19, is insanely hard. They also each have 2 non-summoned minions...