I have nothing to show as my last save of DF is quite old and somewhere on a drive I have forgotten about but I'm the same kind of player as Werdna. I like building pointless and needlessly complicated projects for the sake of building pointless and needlessly complicated projects.
From what I remember most important rooms and main hallways in my fort were two or three stories high with balcony, windows and doors leading to other rooms at different levels, columns, floor paterns of different colours and decorated with statues, artifacts and war trophies aplenty. I used to build temples and taverns even tho the game wasn't supporting such things at the time, elaborate necropolis complete with deadly traps to protect the rest of the deads from the attention of the livings (with the understanding that if it ever had to serve it would probably be the other way around), royal palace, mansions, slums, indoor gardens, outdoor gardens at z-10 with glass ceilling and retractable drawbridge (I know, you don't need one if you have the other, but that's how I roll), market place, public bath (that had to be closed and quarantined because the water quickly became red, and green, and yellow, and filled with filth, blood and syndromes from at least two different megabeasts) and once I decided to build ballistas, which is pointless in and of itself, but rather than just get rid of all the extra bits I had to craft in order to get the required amount of masterwork ballista parts I used them to build two row of 15 or so ballistas each, facing each other in a large hall that was dubbed the "Royal Arsenal" and served no purpose other than to look utterly badass. I even made sure that the arsenal was linked to the road used by the merchants so the ballistas could technically be hauled out of the fort if needed even tho you obviously can't or need to haul a ballista in that game.
So yeah, lots of pointless stuff.
The only thing I ever built that could be regarded as practical was the way I organised production and residential area. Depending on how much of a given item I needed I would either decide to organise its production in what I called a "shop" or a "guild". The shop typically had the work space on the main floor, storage below and housing for the shop owner above that, a few extra bit too if I deemed the job prestigious enougth to deserve it. The guild meanwhile was similar to what production area looks like in most forts I've seen and used for the main industries but the living quarters of the guild members were directly attached to the production area. With a lavish mansion for the guild leader, nice houses for the head of each branches of the guild, more modest quarters for the guild members and dormitories for the guys tasked with hauling everything in and out of the guild. The result was a very decentralised fortress and allowed for the liberal use of burrow orders which stopped my important dwarves from being killed outside on a quest for more socks, saved a few FPS by making pathfinding much easier for the majority of the dwarves, made production very efficient and easy to manage and most importantly gave me excuses to build more pointless stuff like guild halls or a town hall with a meeting room for every guild leader, the mayor and even a representative from the nobility.
Now that I've decided to go back to DF you can imagine that I'm overjoyed to learn that I'll be able to have several nobles and a priesthood and build working temples and taverns, libraries, a foreign quarter, museums, shrines, universities and much more.