Hard to say. But I will go with this one.
In Lew Pulsipher's Tonilda campaign there are two main places of dread: Skystone Castle and Mount Thunder. The party was deep beneath Mount Thunder and already weak when we were hit by an ambush of Pyromancers. After a hard fight they fled and we were out of spells and low on hits.
And the pyromancers had alerted the Ogre King - the entire tribe was on the way to slay us.
We could not leave the way we came in, so we had to head to the arch, a long, narrow, stone arch bridge over a vast abyss. When we arrive it is held by a balrog.
I was playing Andune, my then 6th/6th cleric/magic-user. He was at 24.5 hit points (Lew and I both track 1/2 hit points) but had a good armor class and a Mace of Disruption, meaning I had a shot at disrupting him. I was also the only guy above single-digit hit points.
I read a Scroll of Protection vs. Fire and ran out to fight.
4 rounds later I am at 6.5 hits and he's going strong. We tie initiative. W have the same dex. Same weapons speeds. Simultaneous hit.
We both hit.
I do minimum damage, 2 points.
He does minimum damage - 6 points.
I roll for disruption - natural 20!
The balrog is sent away, I collapse, the party drags my barely-alive carcass over the bridge. We spend 2 hours hiding in a closet to avoid the ogres.
Andune kept the balrog's whip and put it over the mantle at his tower.