I was going to look for a couple of ideas to post for you, but I found so many interesting ideas on Houzz, I kind of couldn't stop myself. I really like the first one and the last one especially intrigues me, with the idea of just one bookcase on the side with the offset mantel. [[(https://www.houzz.com/photos/contemporary-living-room-contemporary-living-room-new-york-phvw-vp~6567) [contemporary living room design[(https://www.houzz.com/photos/contemporary-living-room-ideas-phbr1-bp~t_718~s_2103) by new york architect Coburn Architecture and Interiors [[(https://www.houzz.com/photos/audrey-matlock-architect-modern-living-room-new-york-phvw-vp~18255) [modern living room design[(https://www.houzz.com/photos/modern-living-room-ideas-phbr1-bp~t_718~s_2105) by new york architect Audrey Matlock Architects [[(https://www.houzz.com/photos/boston-architects-eck-macneely-architects-inc-contemporary-family-room-boston-phvw-vp~33471) [modern family room design[(https://www.houzz.com/photos/modern-family-room-ideas-phbr1-bp~t_720~s_2105) by boston architect Eck : MacNeely Architects inc. [[(https://www.houzz.com/photos/woodvalley-house-interiors-contemporary-living-room-baltimore-phvw-vp~170469) [contemporary living room design[(https://www.houzz.com/photos/contemporary-living-room-ideas-phbr1-bp~t_718~s_2103) by baltimore architect Ziger/Snead Architects [[(https://www.houzz.com/photos/stamford-living-traditional-living-room-austin-phvw-vp~98164) [traditional living room design[(https://www.houzz.com/photos/traditional-living-room-ideas-phbr1-bp~t_718~s_2107) by austin architect Hugh Jefferson Randolph Architects [[(https://www.houzz.com/photos/new-england-contemporary-living-room-and-dining-room-contemporary-living-room-boston-phvw-vp~34860) [contemporary living room design[(https://www.houzz.com/photos/contemporary-living-room-ideas-phbr1-bp~t_718~s_2103) by boston architect LDa Architecture & Interiors [[(https://www.houzz.com/photos/home-nest-traditional-dining-room-new-york-phvw-vp~83353) [traditional dining room design[(https://www.houzz.com/photos/traditional-dining-room-ideas-phbr1-bp~t_722~s_2107) by new york interior designer Marie Burgos Design [[(https://www.houzz.com/photos/portfolio-pictures-contemporary-los-angeles-phvw-vp~118723) [contemporary family room design[(https://www.houzz.com/photos/contemporary-family-room-ideas-phbr1-bp~t_720~s_2103) by los angeles interior designer Kashmere Interiors [[(https://www.houzz.com/photos/living-room-contemporary-living-room-austin-phvw-vp~130510) [contemporary living room design[(https://www.houzz.com/photos/contemporary-living-room-ideas-phbr1-bp~t_718~s_2103) by austin interior designer Laura Burton Interiors

Love the color of the walls and that wonderful paneled wall. I agree that the tv is in the right place on the paneled wall. Here is a floor plan which may work for you. Use the space that is not under the catwalk above as the seating area. This way the walk thru will be under the lower ceiling. Tuck a 87" wide sofa with a chaise end on the right of the fireplace with a console behind. Install wall sconces for lighting at the console instead of lamps. Lose the big lamp (it's ver nice) and use smaller scaled floor lamps. Get a matching 66" loveseat and angle off the sofa. this will create a more open layout and not so boxed off from the kitchen. Add two matching swivel chairs. The coffee table is a 48" diameter with four round ottomans or floor pillows. The rug is 12 x 15 so that it anchors the furniture and includes the paneled wall and the fireplace into one cohesive area. Along the staircase wall is 10" deep low cabinet or bookcase up to the ceiling for games, books, etc. Something like an Ikea Pax with frosted doors, simple and functional for storage. Hope this helps.

I think you should ignore it after you have addressed the issues of it looking neglected. Get a new glass door/screen paint the brick white to match the rest of the chimney front and restain trim. Then add some really interesting plants and greenery either silk or real plants and let it give the room life.

To do an L-shaped seating arrangement, I’d position one sofa (or one side of a sectional, which is personally what I’d use) along the south wall. The other sofa/side of sectional would run parallel to the west wall. That means the west wall needs to be your wall for the fireplace and tv. While I had a corner fireplace at our last house and would avoid one again, I do think one would be appropriate for your space. You could still have windows along the south wall for natural light.