My group had to climb down a hill, there was five PCs. First climb roll: everyone pass and climb down half of the hil. Second climb roll: the Pc on top rolls first and fail miserably, the rest fail the reflex roll to avoid the falling body (including 3 natural 1s), we all fell down in the middle of the enemy camp taking a LOT of damage.

I didn't saw this, but a friend told me that once he was playing a halfling, and duringa celebration the paladin NPC (prince of the kingdom) made a joke about him, he throwed a spoon at him, he rolled 3 natural 20s and killed him.