Dwarf Fortress.
I've pretty much finished the main fortress, which I built partially above ground in the form of a massive Norman Keep, complete with a surrounding wall and archer towers to fire down from. The meeting hall, on the third floor, is splendid with statues of gold decorating the area where my dwarves sit in silver-embossed seats and to dine upon golden tables, all while staring through crystal windows at the fantastic view outside. A small military (Barracks and training on the second floor for quick deployment) work in shifts so that there's always someone guarding the front gates, and I have a core group of skilled plate armored axedwarves standing by for emergencies as well. Meanwhile below ground I've constructed a massive underground farming operation complete with a connection to the nearby river for water that involves multiple pumping stations, floodgates, and an elaborate series of levers to flood specific rooms before planting season. Don't even get me started on the sleeping or mining areas.
My plan for what next is to build a massive crypt, unconnected to my main fortress but equally well decorated. Thinking I'll construct the entrance into the upper part of the mountain, near the barren lands.
Damn I love this game.