I own a deluxe house in the Thorin’s Hall Homesteads, a kin house in Belfalas, a Stately Small Smial in the Lyndelby homesteads, and I just bought a home in Rivendell.  
 My current favorite space is in my home in Lyndelby, where I built a hidden goblin cave!
 After discovering that certain decorations had no collision boxes (one of which is the Wooden-Framed Rohirric Double-Swing Window) I used several of these to hide the entrance to a cavern beneath my Smial in Lyndelby. 
  In the hidden cave, I have a couple Fancy Rohirric chairs sitting comfortably to either side of a Dwarven map table strewn with four of the interactive books from Mordor. The central floor uses the Lava Floor from the Moria reputation vendor, while a red light hung above the doorway creates the illusion that the floor itself is glowing, casting reddish light and shadows across the walls and paintings of the hidden cave. A pair of ominous Black Robed Statues bearing Blue-flamed Braziers flank either side of the view into the cavern itself.
  Beyond a low stone wall you see a grotto with the distant fires and buildings of a goblin town. A giant cave claw has chosen the ledge to have a snooze across from an idyllic waterfall. I placed a blue light in the air between the statues to make it look like their eerie flames were casting the glow seen in the cave. This blue light, paired with the underground falls, creates a soothing contrast to the sitting area.
  I imagine a retired adventurer sitting comfortably in his chair, smoking his favorite pipe and reading through his collection of Moria’s Lost Lore while reminiscing — alone or with a friend — about past adventures, or perhaps even planning the next one.
I absolutely love how much work the developers have put into the game and its decorations, down to little details like paintings hanging in my hidden cave reflecting the red light from one side of the room and the blue light from the other. 

Feel free to stop by any of my homes, all visitors are welcome and decorations are enabled.