I am potentially one of the least-efficient, craziest dorfchitects out there. My fortress layouts have some basic principles in common, but that's usually about it. I don't like to get too grandiose with my architecture because then I'd have a tendency to never get it done at all. These are big images, I warn you.
So starting from the top, my outdoor area in my current fort looks like this:
This fortress was built between two rivers and the edge of a lake. The river to the south provides a nice natural defense for the moment, and I made a moat around the rest of the perimeter to supplement that. I like using moats to set up a perimeter quickly, but usually they aren't this wide. The stockpiles are temporary, but I haven't endeavored to set up many below ground. Likewise the mess of old workshops was part of my very first setup and I've simply neglected to remove them. The farms support all five of the local plants; hide root, longland grass, wild strawberries, prickle berries, and dinner bunions. The main stairwell/rampway is a recent addition, and I had to plug the aquifer below to get it through the entire fortress. The old 1x1 stairwell isn't as necessary now but most of the fort was designed around it anyway. The dog pillboxes are for spotting the local threats; dragonman ambushes and kobold thieves. I don't have to worry about building destroyers so much so I didn't raise but one of them. The trap bridge i the south-west is my favorite: that's where the caged animals and dragonmen come from!
This is the main dorm level. I haven't added cabinets to the rooms yet and not everyone has a room, but the dorm to the west is open to all. Between the surface and here is a big jumbly mess of farms and farm-related stockpiles, as well as the trade depot.
This is the level immediately below, where the old dining hall is to the north, and the new one is being furnished to the south. The new one has a row of waterfalls across it, hence the grates, but I've got them switched off right now for maintenance. The new dining hall also features an artifact grate and I intend to install the artifact hematite table as well. I plan to convert the old meeting hall/dining hall into a carpentry workspace.
This is the main clothing industry floor and the villa of my retired legendary werebeast-battlemage-druid adventuress. She's not allowed to leave currently, but she'd have a nice three-story villa to enjoy if she'd stop breaking all the furniture! The workshops represent my most common design; an 11x11 room, usually with three shops along opposite walls and either another three in the middle or a stockpile.
This is the lowest level of the fortress; the smithy. Everything in-between I skipped because it's more a mess of twisting tunnels and water pipes, and doesn't display any new archtiecture. The smithy here is actually pretty self-explanatory, but it's a design I use over and over exclusively for my magma forges and smelters.