The perfect house in NV would be a port over of Dukov's Place with a Vegas twist.
-pool
-working bath
-aquarium
Hope that helped ( :

I think a house mod should have a armory a good place to store stuff and a bed and have clean water source for people playing hard core mode.

for me it has to be practical. located some where other then good springs a place to sleep and a place to store my stuff

Add a creepy seiral killer basement muhahahaha

Skeletons in the closet. Ha

how bout (i know it will require lots of scripting, but sounds like a neat idea to me) rebuild a house and customize it?, like start with a destroyed house and then use certain Misc. stuff to build it it, and once built you can add stuff like containers and lights,beds etc, once you buy em from a vendor or salvage them from the wasteland and then place it "Wasteland defense" style (with a shadow of the object then press a key to place it) or maybe even be able to build from the ground up using custom materials (i know im asking for much, but i always wanted something like those things :p )

Ok for real this time: a gun range with respawning npcs to act as target dummies

I think a good ideal for a house mod would be renovations. Like you can start with a crappy house but then get material to build it slowly to create your ideal house. It can be something lore friendly or not, you may want to build an armory or not, just basically what you want instead of sticking to something someone else made. (Not saying that what others made are bad it may just not be your taste)

Got my own house mod I'm still working on. It's an underground vault/cave and pretty big. What's inside? I've got all the essentials: Food, water storage. For crafting I have a reloading bench, workbench, campfire, hotplate, chem set, garden. I've also got a bunch of storage containers for loot, weapons, and crafting accessories and so on. Beds for resting. Outside there is an area I made as a shooting range and sentry turrets to the entrance to my lair. Inside, I have a Vertibird Hangar that opens up at the top of a ridge, so I can one day learn to fly. I can go on an on with the ideas I have. It's mostly got a enclave vibe to it. Still a work in progress.