One that I can remember on top of my head was...
In DnD, one of my player, a bard, was using a dagger to cut the rope at the lifeboat so they can escape. Well, since there's a pair of Colossal Kraken and Octopus fighting on either side of the ship, and there WAS a storm and pirates raining curses (Mundane, not magical.) around, I called for a attack roll to hit the rope.
He rolled. 20. "Okay, roll again."
He rolled again. The d20 bounced off the table, hit his crouch, and so we rerolled again on the table... 20. "... Alright, roll again."
20 again. "... Mmkay. Roll again."
20 again. Needless to say, the rope disintegrated with one well-aimed deft strike from a bard with a dagger.