Your lighting may improve dramatically if you simply switch to LED's. Try that for starters and see what you think., posting a picture of the difference it makes. Since the windows don't provide a lot of natural light, consider covering them with a frosted glass panel and a light panel behind them to illuminate at will, great for dreary cloudy days. First impression I have is that your TV and book issues can be solved by one great built-in on the wall behind the sofa. A narrow homework spot could be built-in for computer connections and two seats for the boys under the window and soffit in the double door area. You mention "sectionals" so if you want two, I'd suggest you get apartment-sized ones with equal sides and no chaise. Float them in the center of the space forming a large loose "U" and add an upholstered hassock for each that will flex to be rumble seats for the boys if they get antsy sitting for a spell. In the corner where the chair is, install a popcorn machine and a soda machine for ease of entertaining and snacking. Since the windows don't provide a lot of natural light, consider covering them with a frosted glass panel and a light panel to illuminate them at will, even on cloudy days.

I think a large, modular sofa would work well in this space. I like the Togo sofa and I think something similar could work well for your needs.



Since you said you could go for bold, I think you could do a bright, geometric print or photograph as wallpaper behind the couch as an accent wall.

https://www.houzz.com/photos/7th-avenue-parkway-contemporary-remodel-contemporary-staircase-denver-phvw-vp~2934471



This sounds like a really fun space - can't wait to see how it turns out!