I've always wanted a treehouse. Not a little rickety board nailed to a branch, but an actual treehouse, with a roof and windows. As a child I planned that I would need a rope ladder, a trap door and window boxes. Of course the treehouse will also need a light, so you can read in there at night.
I think I found one online that meets my specifications. Maybe E will decide to build it for me. Or my friend Ben, he's really handy with tools.