Single-room with an observation tower, well-defended by some kind of wall encircling a large courtyard that can fit a farm and friendly mob space. All of my bases have some kind of perimeter defense, be it flaming netherrack, a spider-proof wall, cliffs, or a body of water.
To be honest, I'm so used to SMP servers with griefers that even my single player worlds have hidden underground bases. There's basically no structures above ground, the only exception being an iron door peeking out of the side of a mountain.
Soooo pretty much all my houses are underground, extremely large, and hidden. :tongue.gif:
it sounds kind of dull and dreary, but I like them like that. It makes me feel secure. lol
I guess it's not a very cool design for a house, but it's practical for SMP.
Edit: went kinda offtopic lol.
Multiple floors: YES. BOTTOM FLOOR HITS BEDROCK. That's where I store stuff. Top floor is right underneath the grass, whatever height that may be. If I'm really paranoid on smp, I'll dig about 30 blocks down and then start building there.
Specific rooms: Not really. There's your basic furnace/crafting room. Never more than 6 furnaces and 1 workbench. More practical than aesthetic I suppose. There's the bedroom. Wheat/Sugar/Cactus farm around 10 plots for cactus and sugar cane, 20 for wheat. (Im not describing a specific house I have, but all of them:p) And tons of empty rooms mined out. Wtf I'm weird.
I always make a Large first floor and a second floor that covers half of the first floor so i have a huge balcony.
I made an obsidian bunker too. in theory if i was teleported to my minecraft world only to hear of a nuclear blast i might survive.