This is the room that I really haven't done anything with. Its an awkward long skinny space and I'll be honest I just don't really need it. I had some extra furniture so I made a little reading nook on one end....that I never use (I read in my big comfy chair in the living room).
The other end was converted to my workout room, which I never used until recently. Now I use it at least 5 days a week and its totally worth having it!