Do you live near an IKEA store? If so, have a look at the BESTA series for ideas. On line at www.ikea.com

Thanks! I thought about mounting the tv on the wall with a swing arm. That way it can be pushed back flat when not in use. Do you think I should come out the full depth of the nook?

That is better answered by the media pros on this site.
I see there is a duplicate thread running.

I'm not sure how the double happened. Got an error that said could not post at this time, then when I tried again there was 2!

FYI sort of off topic, but you could cut off the top of that yellowish cabinet and make a cute side table, tv table or wine storage rack. Good luck.
Also, I don't favor too much built in stuff because styles change with time, and it is easier to change furniture, but in your case, it does make sense.

Hang the television - and then find a deep cabinet that can run left to right in your niche. I think the yellowish cabinet is begging for an accent color - green would work in almost any color scheme - something like sw koi pond - to display some photos, books, objects of interest or a collection. Definitely belongs on a higher wall with that interesting capital - don't take it apart - would be darling near a casual dining room to store dishes, salt and pepper, placemats, cake stands, etc.

Thanks for advice! I have another wall between two windows that I will move that cabinet to. I have the matching desk as well. I'm going to paint all the walls a deep grey.

For the best look, I would personally do "built in", which means only that the shelves are permanently attached, with moldings for clean edges and matching your current finish materials.

Start with the placement of the tv and design around it. Your shelves don't need to be that deep, so I would consider a banquette/reading space next to the tv, with book depth shelving above it. Pull out drawers beneath the tv and banquette for games, throws, pillows, etc. Remember to add suitable lighting and outlets. It can be a very usable space if designed well. Good luck

[houzz=[https://www.houzz.com/photos/new-york-city-pied-a-terre-transitional-living-room-new-york-phvw-vp~7018815[(https://www.houzz.com/photos/new-york-city-pied-a-terre-transitional-living-room-new-york-phvw-vp~7018815)]

[houzz=[https://www.houzz.com/photos/telegraph-hill-home-contemporary-family-room-san-francisco-phvw-vp~23863884[(https://www.houzz.com/photos/telegraph-hill-home-contemporary-family-room-san-francisco-phvw-vp~23863884)]

[houzz=https://www.houzz.com/photos/rathgar-dublin-contemporary-family-room-dublin-phvw-vp~7196993]