Well my first home was a hole in the ground with a separate room for a bed and storage and door leading to a mine. However it evolved from there so that this part was only my basement with my main mine entrance, second bedroom, workshop and storage room which and had an iron door and tunnel leading to an impressive cavern that held my inter-dimensional portal. On top of that was a nice two-story home with a fantastic yard with its own waterfall, a small farm to grow cane, a jetty to launch boats and fish from, a vast deck with a modest wheat farm and of course, a sky-scraping doom tower. Added to the ground floor was another area which included a staircase to my indoor arboretum which grew trees for me to harvest wood from. It also had a staircase and tunnel down to a machine that generated stone, (I wanted it to generate obsidian, I didn't realise that was impossible.) The second descending staircase led to a long tunnel that went under the sea to an underwater lounge to which I added an ornamental lava-fall. My next step was probably turning this into the start of an underwater doom fortress.
But then it vanished. No idea where it went. I was pissed off and haven't played Minecraft since.\
I should also add that the gargantuan house was predominantly stone, not cobblestone, meaning I had to smelt each block. It was a significant task and I was rather proud of the result.