A black, modern-looking unit under the TV would give the section of wall a unified purpose. Don't bother with an accent colour, just let the furniture do the talking.

Should the unit be built into the wall?

Any other suggestions?

What are you trying to accomplish? Drama or function...?

Your tv appears to be mounted too high. Is that the only wall it can go on?

Where else should I mount it?

Well, I don't know. That one part of the room is the only spot you posted. :)

You need a wall unit that will have the TV at the appropriate height (too high now), an electrical outlet so there are no hanging wires and hopefully room for the components at the bottom. If the space can't accommodate the depth needed for the components some narrow drawers at the bottom could hold DVDs. There are all sorts of examples on Houzz (they are all bigger but the concept is the same), you just need to scale down for the narrow space. It will probably need to be custom, but custom is not as expensive as you might think. Many furniture stores (especially the independent stores) will do custom. Nearly every piece of furniture I have is custom since I am space challenged too.

Find a console to either set the tv on like this ikea unit, or lower the tv and hide the cords with something like the system I posted here. The console should not be wider than that wall. You'll have a much neater media area with the cords hidden. :)) http://www.businesswire.com/news/home/20130814005965/en/Hide-TV-Cords-Student-Housing#.UxkvFaN5mSM

I like the idea of installing an electrical outlet behind the TV to hide the wires. I'll remember that for a living room renovation I'm planning where I'll have no choice but to wall mount the TV. Thanks for the idea!

You don't need to use a media console. It could be a low dresser. Just so it is deep enough to safely hold the tv if you choose to put it on top of the console.

I like the way this one looks. Very contemporary. It may be too long for your space but there's bound to be one out there that will fit :)

Please take the TV off the wall. Looks strange. Get a media center Ikea sells that will fit in that space. Put TV sitting on top of it. Put components out of sight as well as wires. This is not working as it.

Best height for the TV is to have the bottom 42" from the floor. A piece of furniture below to hold components is nice and if you want to get into the drywall, you can put a plastic channel inside to hide wires from the TV to the components.

Get an electrician to run those wires in the wall and then you wouldn't have to put anything under it.

Thanks for all tips. Do you think a hanging cabinet like this would be good?

That would be great! Make it wider than the tv so it will look balanced. That is such a small area that anything solid like the dresser I posted above would look more clunky than the floating unit you posted above. Find one that looks cool. Take into account that the tv should be 42" off the floor as Driftmier Design suggested. Post pictures so we can see how great it worked out :)

You can do a hanging cabinet if it is at least as wide as the tv. A bench no wider than the bump out wall under your tv with the vertical components to the side will work too. Just ground the wall. I think the wall would be amazing with some chalkboard paint and perhaps do just the face of the fireplace too. You have a uniquely contemporary place with fresh lines - so you can push the boundaries more than most and have it work.