What we've established (me and my parents) is this...
They've wanted to do it so they aren't too strict as far as money (wish I had known this before bitching about a new gym membership)
A Power Rack with
1 Good Barbell
4 45lb discs
2 25lb discs
4 10lb disc
2 5lb disc
2 2.5lb disc
Storage Pins on the sides of the rack.
Many placement slots for the safety pins
A Pull-up Bar
An all purpose bench
A cable weight thing on the back of the rack
We have a dumbell set with 2 dumbbell bars and a EZ-barbell or w/e and like 2 10's and 4 2.5's
Medicine Balls of varying weights
A swiss ball or 2
We have a tread mill
We have a stationary bike
Mirror'd Walls around Power rack
and a mounted flat screen for cardio machines
I'll demand a stereo down there
Possibly some of the 1ft by 1 ft interlocking mats if they're thick enough.
But thats what we've got so far. I'm pretty pysched my parents are so on board