Your' best Lemon aid, please!

Every so often a party gets into a situation that they simply can't win. Sometimes they're as small as missing a killing blow and the hostage getting away, sometimes they're as bad as a TPK of a party that doesn't want to lose their characters. When the worst case scenarios come to bare on a campaign a good DM will give a party that wants to go on a big bag of lemons to work with, which sometimes lead to the most interesting character evolutions or opportunities. Maybe your character lost an eye after your party lost an engagement, but it was latter replaced by an Artificer which later led to scenarios even the DM didn't expect at the beginning. So, to the folks that get to play on a regular basis or have long standing campaigns, what are some of your worst roleplay encounters that led in interesting directions?

I had a rogue in one of the games that I DM'd. He accidently killed a town guard at level 1. Totally unintended. He had to flee as they hunted for the murderer. Later another townsperson was slain and he was discovered nearby and blamed even though he didn't kill them. His reputation suffered miserably and he was hunted throughout the land. He started as a pseudo evil thief. But due to the constant pressure, lies, and persecution, he was sort of forged into a character that had to champion his own cause and convince the world he was not a monster. By the end of the campaign he was a champion of injustice and crusader for the falsely accused. He essentially became a neutral good character. In the beginning of the game he just sort of had to run and survive. In the middle of the game he railed against the injustice against him and why he had been so miserably displaced and sought out like minds. In the end of the game he returned home to deliver justice to the land and protect others that would suffer a fate similar to his own.