I've had a couple. I've incubated a total of 19 eggs this year, and only one has been a boy. He was a Turken, ugly as sin, so I was going to give him away anyway.
My definite luckiest time was this summer. I stayed up late one night, don't remember why, and was sitting in the living room. It was probably about 11 pm when I heard panicked chicken sounds from the yard. It was the one night where I thought "eh, the chickens are probably in the coop." I ran outside and got there just in time to find a possum running away from the chicken coop where my favorite hen Peebles was roosting on top of. She didn't get into the coop in time before it was too dark for her to see. She was about 20ft away from the coop in my yard, unharmed, but had all her crop feathers and some tail feathers pulled out by the possum. She did go into shock, but was fine after a night inside my house. I go make sure the chickens are up every night now!
Another one was when Hurricane Ida hit down here in South Louisiana in late August. I had 3 eggs in my incubator on lockdown and was freaking out. I wrapped the bator in blankets and an emergency blanket. We ended up not having power for a week. I took the bator to a friend's house which still had power the day after the hurricane, having already given up on any hope of them hatching. DB went to that house to mow a few days later, called and said "Um, there's a chick?" I was shocked. About an hour later, he calls back. "There's another one." Flummoxed. Right before he leaves, he calls. "You're not going to believe this. There's three chicks in this incubator." I was absolutely shocked. Nothing but the grace of God kept those eggs alive. Those babies stayed in our house, which was conveniently at about 90 degrees with no power/ac, and stank it up, but that's a small price to pay for miracle babies. One ended up being a boy, and the other 2 were girls.