My favorite fortress is one of the early 40d variants, named Thobtishak. IIRC, that means ShipKillers or ShipArdent; I was inspired by BoatMurdered, as were so many of us.
Anyway, I'd been avoiding Thobtishak for a while due to OH GOD GOBLINS. I finally reopen it, and spend a while having my team of six legendary miners dig about, training others, et al.
Finally, I get to the point where I can't really do anything else; my tower is getting pretty tall, but I've run out of wood to make beds, can't find any more lignite to burn into coke, and the remainder of the areas I wanted to dig out were all boundary walls to the outside.
My military was smaller than it might have been, but nevertheless a force to be reckoned with. I take my most promising (read: any) Recruits, put them under whichever soldier has kills to their name, and build a set of airlocks so that any gobbos that might get past them wouldn't get any farther than my trap-filled entrance hall.
By the time my squad of dorfs get outside, I notice the goblins have left. Confused, I look up-and notice that the Siege tag is gone.
While I'd been preparing, the goblins had evidently decided "screw this" and left, the whole shebang of them heading to the north.
They killed four of my favorite Masons and one of said masons' kids. I'm kinda pissed that my dorfs didn't get revenge.
Thankfully, a Human caravan showed up to ease my frustration a bit, and there was still a great variety of wonderful things from the Goblins. My remaining Masons set to work building the things I'd designated while waiting for the gobbos to leave, and I relaxed.
I need to get enough old computers to finish my Beowulf Cluster so I can PROPERLY flood Thobtishak's Primary Farming Complex. Half-muddied, it has nine full-size farms; fully muddied, I'd be able to clean out the caravans even more thoroughly than I do already!
For an idea, have a look below-even though it's been expanded since.