I've got time for a few stories:
1.) Back in the 1E AD&D days, on my very first adventure, I was playing a 1st level thief in a game with my older brother and his friends, 7th or so level PCs. They forced me to climb up a 200' tall cliff and lower a rope ladder down to them. I somehow managed to climb the entire way without falling, secured the rope and then waited for them to climb up. Just as they were about to reach the top, I cut the ropes and let them all fall to their deaths. When the DM asked why I did it, I said "I'm the thief, right? I steal, don't I? Well, was I going to get more treasure from some mysterious dungeon or from killing those guys and taking all their gear?"
2.) In the early days fo 2E, I was playing a 7th level paladin in a party that had just liberated a small village from an army of orcs. As we were floating away in our hot air balloon after the battle, we spotted orcs returning to the village ... with ogres. Realizing that there was no time to bring the balloon down before the orcs and ogres reached the village, my paladin jumped down from tha balloon to try to slow down the monsters while the PCs lowered the balloon and fought with missile weapons. After the fall, the paladin had 3 or 4 hit points, but managed to kill 4 ogres and 10 orcs before death took him. That goes down as my favorite heroic death for a PC.
3.) An accidental TPK: We were fighting against an army of drow. One of the drow, a cleric created darkness around himself and fled after one of the PCs managed to silence him and poison him. He fled around a corner and down a tunnel onto a cliff inside a huge underground cavern, but died to the poison just as he reached the edge of the cliff. We finished off the rest of his allies and raced after the cleric, not knowing he was already dead and not wanting him to get away with valuable treasure (or to warn the other drow of our presence).
The party moved at different speeds (monk, barbarian, rogue and halfling wizard), so we ended up splitting up a bit as we raced after the cleric down the previously unexplored tunnel. The monk arrived first, saw the darkness sphere and rushed in to find the cleric. The DM took him aside and quietly and provately ran the next few moments. He ran right by the cleric, off the cliff and fell to his doom. Nobody heard the death screams or saw him fall because the silence and darkness blocked the view.
The barbarian saw the monk enter the darkness and rushed in to offer assistance. The DM pulled him aside and ... splat.
The rogue was next. He was afraid that he'd miss out on his chance to loot the corpse, so he met the same fate.
My halfling was last. I ran right off the edge, just like the other three. It wasn't until a few hours later, after we had rolled up new characters, that I rememebered that my halfling had on a ring of feather falling ...