(40d) My fort was going swimmingly. Any demands the nobles had, I could fulfill. I had walled off a large section of the surface for my own amusement, and my wrestlers could tackle horses out from under their riders.
Then a dragon came.
Rather than risking a massive forest fire, I told my military to stay at the bottom of the entrance tunnel, awaiting combat. The dragon came running straight for my entrance... and got himself caught in a cage trap. I then had the dungeon master tame him. This ultimately payed off when said dragon single-handedly routed a siege some years later (via sweet fiery death).
In my latest fort, when a single, wimpy speardwarf, presumably in a fit of alcohol-induced rage, routed an ambush of goblin macemen by himself after killing only one of them. I don't know what was so terrifying about this dwarf, but damn that was awesome to watch.
A mild one in adventure mode recently, when I was caught alone at night by bogeymen while some 10 map-tiles away from town. What ensued was a frantic race across the plains that lasted almost until morning, with my adventurer lopping off a leg from any bogeyman that caught up to him. The message of "the cackling fades away" felt like sweet, sweet victory.