Simplest would be shelves straight across high enough and deep enough to accommodate baskets, like the ones they sell at Ikea or Pottery Barn. That way you can use different colors or materials to make it interesting, and inexpensive to change them out as they get dirty or you want to change the look of the space. Another option would be to do basic cabinets to keep everything "behind the scenes" and maybe bookshelves on either side of the television. For either option, leaving shelf space under the tv to accommodate cable boxes etc.

What about base kitchen cabinets for the bottom half and open shelving with space in the center for the t.v on the upper half? They are inexpensive if you buy the basic ones and can diy the install and painting. Some extra moulding would make them appear custom. An unfinished base double cabinet at Lowes (36 inches) is $139. This hides clutter and extras like blankets and board games, but with the open option up top for further design and function.

Thank you both - we had intended on doing shelves on the sides and cupboards along the bottom problem is we can't find pre fab cabinets that fit from ikea, lowes or Home Depot but we are still on the hunt! Thanks again for your advice!!

Are the pre fab ones that don't fit too deep? Not deep enough? Not wide enough?

I don't think you need to lock yourself into making it look built-in. A nice piece of furniture and/or set of shelves/cabinets would look just as nice, and would expand your options.