My favorite thing of all time to do, ever, is My extreme execution towers. I'm not talking about little ones, like 10 z=levels or such, I once had one spanning 30 (there were no caverns for a while) z-levels (before the fort fell) and along with that, it would be a lot like a tunnel going up and down, starting big at the top and bottle-necking as it goes lower, each floor containing workshops and/or dwarf bedrooms as well as the various barracks scattered throughout. I always executed the more "honorable" enemies (goblin weaponmasters) by placing them on top of this tower (1x1 wide/tall), (there were high quality iron menacing spikes at the bottom) and training my marksdwarves with a suspended platform nearby this in order to kill it very, very dead. Just wait for them to dodge, then they tumble down and down until splat, then the dwarves can clean the body (it would have already been stripped of clothing) up from the floor, as well as the blood and vomit, if they somehow survived to throw up once they landed.
Optional: put rowdy dwarves up top and fire away with ballistas/catapults. They will have no choice but to either dodge or get shot. either way, mission accomplished.
I love doing smaller versions of that, but usually goblins end up killing the hell out of my dwarves before tehy can do anything about it. I commonly have a smaller execution tower/funnel system where the dwarves end up swarming the bottom because it is the quickest route to the other side of the fortress, I include a lot of staircases.
Oh, also I have my trap hallway. How I describe that is 'no dwarven day is complete without the fresh smell of miasma in the morning.'