Given the wood paneling, a white/cream couch is probably the best option for the room. Funny enough, that is what the original owners had in there. The blue recliner I still have should go in here too. Also the entertainment center will live here.
Maybe something like:
The brown couch and loveseat (above right photo) I still have will go in this corner. Maybe the office desk too behind the photographer from the above left photo.
Think of getting curtains for the doors into the sun room.
Thinking of painting the shelves white.
The Great Wave Off Kanagawa painting will go in this room above the shelves. Along with a koi and other painting.
Need a table for this room.