Well, although it seems that the thread has far derailed from its intended purpose, I'm going to post my first (and favourite) tantrum spiral.
This was in a fortress whose name is long forgotten, and whose works long lost.
It was my first fort to reach the point where it had a mayor, the first to be attacked by gobbos, the first to reach 80 dwarves, and the first where I had a go at building above ground.
All was going well. There was a surplus of food and booze, I had a steel industry starting, and the ground floor walls of my 'castle' entrance were done (complete with water filled moat and drawbridges). I had a bunch of cage traps protecting the inner part of the drawbridge, a courtyard with trade depot and a beginning military, with steel plate and helmets, which had completely obliterated a goblin ambush.
And thus started the decline.
It began with the goblins, it always did. Shortly after my military's rather easy victory over the ambush, another one popped up, getting the drop on a hunter and a child who was playing outside the moat. By the time my soldiers got there, it was too late. Unfortunately, as my soldiers advanced to exact revenge, they triggered another ambush. With a marksgoblin in.
It was then that I found out that steel plate only covers the chest. That goblin shot EVERY SINGLE ONE of my ten-man military in the left leg. The wimps then proceeded to pass out from the pain, and we're duly murdered by the meleegoblins.
I promptly ordered my miners to form up into a scratch squad to make a last stand. The goblins chose that exact moment to run into the cage traps.
With that crisis over, nothing much happened. Oh, sure, someone starved themselves to death, but nothing much to worry about.
My fort would probably have recovered had corpses mysteriously drained of blood started to turn up.
Foolishly, I ignored the signs. Bad move.
Another couple of corpses later, and my fort was still, somehow, happy. (thank you, legendary dining room). And then a child was the next victim.
People started tantruming. Tables started being thrown, statues began to be toppled, two dwarves went nuts, and another three went berserk and had to be put down by my war dogs and the miner militia, who were, on the whole, content.
I immediately ordered the still sane dwarves to begin dragging as much booze and food downstairs as possible, in preparation to lock off the remaining sane dwarves.
While all this is going on, my expedition leader/mayor made my favourite artifact ever, in what I like to think of as a desperate attempt to reclaim order:
"this is a large, serrated, dwarf bone disk. It menaces with spikes of dwarf bone."
To this day, I have no idea what dwarf was made into that. It could have been a smith, it could have been a cheesemaker. Heck, it could have been the vampire!
This was just before I dug into the moat from below.
Preview EDIT -apologies, I've just realised how long this is. I could break it into spoilers if it takes up to much space.