Halfway through the stack I was reminded of my copy of Ostrich Walk / At the Jazz Band Ball from the ODJB, a personal favourite! Unfortunately, I got it in my first month of collecting, and did not know how fragile 78's were, and when I dropped the record it left a nice chip on both sides. Still plays, just missing about 5-10~ seconds.
I've also broken a 7" Columbia through carelessness, and my father broke an Edison blank by clamping it with pliers.
What about you?