I would put a half wall trim with wainscot ( or fake) and then assemble some frames different sizes like so . I would cover that coffee table and make it a soft foot stole ( plenty of ideas on Pinterest :)

Please take a look at my collection of abstract art. You can choose by color or by type. Let me know if you like anything and we can go from there http://alexeirebrov.com

Large art work is an idea but make sure you don't clash with the oriental rug.

Try painting an accent color - something dark or jewel toned as in Kathy's example above. I would warn against grouping small pictures though - there's no place for the eye to rest and things feel cluttered fast: if you're creating a picture wall, you'll want to include some large pieces - I think I've seen an article on houzz about how to create a picture wall - a great reference if you decide to go that direction. Another thought - wallpaper! There's an article about wallpaper feature walls on houzz too...

Some art above the sofa that matches the rugs color theme

try one large painting or a group of three in proportion to the seat or one large painting with a set of six small pieces again proportion to the seat

Forgive me if I'm being duh, but what is the item of furniture that is blocking most of the entrance to the room? It looks as though it might house anything from fish to boa constrictors. Does it have to be in that position? Is it built in? Very intrigued by this dilemma ... thinking ... thinking ...

It's built in I think cuz look at it

Yes it's a built in soon to be salt water tank

i love etsy for reasonably priced and unique art. I would recommend searching "large wall art" and go from there. you can even commission original art in any subject that interests you. I would go with a grouping of three at least 16x20 each. btw i have the same rug in my dinning room. you could play off the deep red, the golden tones or even the bit of earthy green in the rug. i do think the chair rail and suggested small groupings from another post is too small of a scale and will compete with your beautiful built ins and the modern artwork suggested by Alexi is too modern for your space. i see where quercus2 is going. the black and white looks great with red but that may be too oriental....just my opinion its always most important to find what speaks to you, have fun this is your chance to express your individual taste.

I would try grass cloth wallpaper to give texture or depth to the wall. Nothing colorful, a neutral shade. Alternatively you could try a texturizing painting technique. Again, not necessarily colorful or extreme because the rug is so high impact. (Although something with flecks of paint the same color as the red in the rug might be nice.)

Then I would take a tall floor palm and place it near the tank. Foliage would enhance the tank and of course, the height would break the length of the wall.

I would then shop for a floor screen - bamboo or a two toned wood perhaps - to set on the floor at an angle in front of the wall and partially behind the couch to blend from the large dark items in the middle of the room to the lighter wall space behind. (As a bonus , it would hide the wall outlet but that's not why I'd put it there. :-) ) The contrast is too great right now, I think you need texture behind the brown couches more than color. Also, there are a lot of horizontal lines with the top of the couch and the brown trim on the wall. A tall palm and a screen would give more vertical lines. I would not put a rectangular piece of art there untilI I had balanced out the horizontals.

Photos of other wall would be helpfull. I'm thinking a TV is on this wall since the couches are grouped like this. Also some people on this site draw the room on graph paper with 1 box on the graph paper equaling 1 foot. Take a photo of this drawing & post. If u could measure the couches & draw those on the paper it would also be helpful. Is the glass sided rectangular piece movable or is it permanent? What is inside it?

Done thinking. And drawing. I feel the wall needs to be made into a feature itself, and I think if you could get three simple screens made to attach to the wall, stained to match your wood, that might look really good. As below.

Great big marine art to go with your fish tank:

Don't worry about artwork not going with the oriental rug. I've put really bold, bright abstract art with an oriental rug. As long as they have one or two common colors, it works great.

How many feet are behind the couch-- couch to wall in question?

The wall is set back from the wall so you could buy a console or two for below. You'd have some more storage and a place to set your dog treats, with art and shelving above. The picture below is in a dining room, but would look great there.
Side note, I thing I'd turn that corner end table so the drawer faces the tank and is lined up with the arm of the chair.
Maybe a tray or a box for remotes or candle on the coffee table and throw pillows.

I'm assuming your adorable dog is in front of the fireplace, but do you have a tv there as well? Is this arrangement of furniture final or could it work another way? Just trying to figure out if you could use more storage as well.

I'm in agreement with giving the wall itself attention, rather than artwork or furnishings, based on what we can see. It might be as simple as a darker wall colour up to the molding! I also think your rug could run the other direction, and that a larger coffee table woudn't be amiss here. I very much wish your fish might come into the room, and wonder what they have done to be ostracized:
http://aquariumprosmn.com/wp-content/uploads/2009/11/badfish.jpg

It also looks as though the two sofas may be the sticking point, so I am going to suggest that one of them be ostracized instead, if need be( the one that I am guessing faces a fireplace), so the fish are allowed to watch TV with the rest of the family, and that the seating group face the corner, rather than the TV wall, to make space for the little bloaters. While I am making up walls I can't see and spending your money, then if the second sofa doesn't fit that way either, I suggest chairs on either side of the remaining couch to fill out the grouping. And a cushion for the window seat, of course!

Studio 1001, I do love to log on to a giggle. That's a keeper. Another thing that might work is to put one of those gorgeous textured grass wallpapers up there, to carry the tropical feel of a saltwater tank through the room -- though I do like groveraxle's fish art. We're assuming, of course, that the fish are pets and not supper. But then anyone who has such a huggable dog wouldn't think of breeding supper in the living room. I also like Maguire's consoles and shelves, but they might make that passage behind the sofa feel a bit crowded. But I still fancy my screens, durn it, even if I did draw them a bit squiff.

(I fancy them,as well, Rina!)

(Thank 'ee kindly.)

I was first going to recommend a sideboard of a large scale since u have large sofas in the room and add a lamp on one side or do symmetrical arrangement w/ tall hefty lamps on each end w/ artwork hanging between the lamps or to one side if you do one lamp. There may be too many rectangles in the room to recommend this. I do like adding some lamps or a lamp on that wall.
Another idea would be to place a large armoire on this wall then hang artwork on each side of the armoire. It would be nice to have 3 things on each side (a symmetrical arrangement). For example, 3 paintings on each side vertically arranged.
I don't know the length of this wall, but maybe you could have a big armoire off centered and a round table with a chair beside it. Place artwork above the table with a lamp I like getting a lamp on that wall, is possible.
Check online for recommended width in a room which is needed for a walkway between pieces of furniture so you don't make it too narrow.
Also, the table between the couches (in corner) should be larger since your couches are big. A lamp on this table would also be nice especially if u have a floor outlet so the cord wouldn't have to be stretched to a wall.
I don't know what is on the wall the couches are facing, but one needs to balance the design in a room. For example, if there appears to be a lot of "weight" on one side of the room, one needs to visually balance the other side.
Look at home decorating magazines to get ideas for your wall also.