I have quite a few of these, on both sides of the battle.
Stuff that has happened to me (all of which in the past year):
1) My High Elf Lord on a great eagle with dragon armor was challenged by skulltaker. He got 3 wounds through, none of which were killing blow. I rolled my armor saves: 2, 3, 3. "Okay," I said, "I have a re rollable armor save!" Next roll: 3, 3, 3. "Well then," I remarked, "you have flaming attacks, so I have a 2+ ward now!" I picked up my dice, and to my eternal despair, I rolled: 1, 1, 1. Dead general.
2) Razorgor charged the flank of 20 elven archers with a LV4 mage. My unit lost by 1, was steadfast on re rollable leadership of 9. It broke anyway, and ran a whole 2 inches, and was caught.
3) 15 gnoblars charged the same 20 elven archers with LV 4 mage. I lost combat, broke, and was run down.
After that, I gave up using armies that actually have to take break tests.:konrad:
4) But then! I was using vampires. My orc opponent cast foot on my BK bus with general. He rolls a hit on my general, I fail my LOS, fail armor, fail 4+ ward, 2 wounds dealt. He makes the roll to place again. He rolls a hit on my general again, I fail 2+ lookout sir again, fail armor, fail ward, dead general, and most of my army crumbles.
Stuff that I have done:
1) 10 elven archers dropping 4/5 knights with 1+ armor save.
2) redirected a khorne marauder unit of 50 with dogs, in a way to show their flank to my zombies. Zombies charged the flank, won on static CR, broke them, and ran them down! Not bad for what started as a unit of 20 zombies!