Tasselhoff Burrfoot in one of the 1E Dragon Lance adventures falling off a good dragon during an ariel battle over the city of sanction and landing in a Lava river so his body could not be recovered and raised.My biggest rpg heartbreak happened with Star Frontiers. I was really into the d100 system and the primary plus secondary skill builds. I hand drew many new equipments, robot models, ships. Bought several official modules. I was designing a BIG space opera campaign. This is going to be great!
After two games the players didn't like the game and told me unequivocally they wanted to play AD&D instead. The first heartbreak is always the hardest. I've had RPG rejection in later years but it didn't hurt that much. I DMed AD&D but wasn't really into it. Took me several months to get back on my feet.
What is your biggest RPG heartbreak?
[edit: typos]