First off, I am disqualified as a DIYer, But I thought I would post this to show what you can do with some basic wood working tools:
Key: A table saw and compound saw is all you really need....
This is what we call a "cost-effective" ... built in unit (to the right of the fireplace) We installed it inexpensively for the home owner on an addition we built.
Sides of the unit are paper faced 3/4" MDF board (from 4x8 sheets). Shelves are made from MEDEX high-density 3/4" MDF board (from 4x8 sheets) edges all rounded over with a palm sander. Adjustable shelving racks from H.D. The upper trim is basically bed-molding (Narrow crown-type molding). The vertical centers of the unit are fluted trim. We are fabricating doors to install on the lower portion of the unit. The back of the unit is the sheetrock wall.
All will be painted with a color to match the trim work in the addition (including the back wall sheetrock) wall of the unit.
When completed, it will look exactly like a high end, custom 'built-in' unit for about 1/3 -1/4 the cost. (Normally, we would have built this in it's individual sections at the shop. Used all hardwood materials, high end hardware for durability, custom painted it at the shop and then transferred it to the site for careful assembly and filler-trimming = $$$$.$$)
(Side point: Flat screen TV is to go over the gas fireplace with the wiring going to the lower left corner of the unit for the receiver and amps....)
FWIW: I posted this on here to encourage DIYers to see what can be done with some basic tools and a little patience....really, 'anyone' can do a project like this....