This is a relatively small room -- photos are always deceptive and make a room look bigger than it is.

Media Center: the various heights of the bookcase, tv console and whatever is at the end (stereo?) are too choppy and distract from the clean lines of the room. Although the console is useful, if you need a place to put the rest of the stuff, I suggest you replace it with something, perhaps a custom-made, cabinet that spans the whole room. Given your floorplan, there isn't anywhere else to put it. Wall-mount the TV. You'll be amazed how that unclutters.

Furniture: it's all too big and eats up floor space. From this perspective, you have wall-to-wall sofa. If you are in a position to do so, replace the sectional with one sofa about the length with its back to the camera, and a couple of comfortable (not recliners) chairs. A big round ottomon will work well as a coffeetable with the use of a tray, but a round coffee table will break up all the "square-ness" of the rest of the furniture. If there is room, a long skinny table behind the sofa will give you options for a lamp (plug?), a place to set a glass or book, etc.

This will give you a cozier aspect, with options for art, side tables (keep them relatively small), lamps.

THe room lacks a defining color scheme. Since it's small, light-colored furniture is good, but punch it up with pops of color -- pillows, a rug, perhaps changing the draperies, art.

I would leave the tall bookcase where it is, then place the other “bookcase” (TV stuff organizer) and then the console. This would give a nod to the beautiful designs of Japanese Tansu chests I’d place the tall yellow vase on top of the large bookcase (remove flowers) and fill the shelves with the books and other vases you have. Not too much on the shelves, just enough. No decorative items on the other “bookcase” or TV console. I like only 3 pillows at the corner of the sectional. I agree that a narrow table behind the sofa would be nice. I agree there is too much “squareness” in the room, but a large round tray on the square coffee table would fix that problem. TV needs to be adjustable so it can be seen by everyone without getting a sore neck.

Thanks for the comments. I agree the room is small, and very square. I'm not sure about moving the TV to the right corner, it would be hard if I upgraded to a bigger TV. I'm hoping it can stay center.

If I were to design this space I would probably get rid of the bookcase and shelves on either side of the media center leaving the space looking cleaner. I would then mount the TV on the wall centered above the console. I would get rid of the sofa idea altogether and do three to four small swivel chairs positioned around a circular ottoman. Lastly, I would hang a decorative chandelier/pendant over the ottoman providing not just light, but the special designer touch every room needs. This would open up the space and give it a multi-functional purpose (conversation, listening to music and watching the TV).

Unless you already have a door at the top of the stair, I recommend installing one so you do not bother anybody with watching noisy movies/games/sports. Also, this room has some very bad acoustics, too many hard surfaces and a square plan that will amplify lower bass frequencies. You need acoustic panels, plus some panels that have an effect on the lower tones, so-called "bass traps".