I would love to see Bloodengutz back in some form, whether as the icon or just in a sequel house. Great character and a strong premise.
I know RUN went for the whole 80's thing this year, but I'd like to see something a little more overt. Maybe some kind of house set in an 80's arcade. Make it scary and fun and colorful, but not necessarily 3D.
I'm not sure if HHN has ever touched on the Civil War, but thats something I think could be very intense.
And this is really just wild wishful thinking here, but I would love to see Pink Floyd's The Wall made into a house. I know it would never happen, but I can't help but think about how amazing it could be. The animated segments of the movie have plenty of crazy looking characters to use, the soundtrack is already written, and I can't help but imagine how creepy it could be to walk down a hall made entirely of those iconic white bricks with that equally iconic riff playing on an endless loop.
Again,this is just blind wishful thinking on my part. I think we all enjoy a little armchair imagineering once in a while.