As far as me, I've been in exactly one RP that actually ended and didn't die, and I was so proud of it. Half the genetically-modified creatures got blown up to destroy the lab where they'd been experimented on. It was epic and gory and glorious and heart-wrenching.
The sequel, unfortunately, was all downhill. A blind, deaf eight-year-old died of an infected gut wound; her twelve- and nine-year-old sisters were killed by a crazy psychopathic murderer who was also half-creature, leaving behind a six-and-a-half year old sister who went crazy from the loss. Then another went crazy from losing the only other bird-girl, the GM's ghost (since her character had been killed in the explosion and she didn't make a new one) drove half of the others insane and the other RPers entirely lost interest because of how dark the storyline became.