I think the yellow and grey might bring out the gold-ish-ness of the couch.. I'd try to go with more blue colors.. Maybe some navy pillows and a rug with the blue in it as well. The curtains, that ying-yang rug, and the lilac rug just gotta go.. They're dwarfing all the sophistication this room will be able to have with that tile floor and those big beautiful windows. I love the dining room chairs!

Love the armless sofa-bench! Try using it in the center as a "cross-linking" piece between the sofa and chairs. That way people can sit on both sides of it, conversing with the sofa people and the chair people. Put the chairs where it is and use the side table from the left of the pic, or the one with flowers, between them. You'll need one huge rug to anchor the space or two smaller, and very similar ones, to put on either side of the blue sofa-bench. The other two side tables are too tall and too short for your seating pieces, so ditch them. Use your coffee table between the sofa and armless sofa (18" away from each of them.) Here's a chart for judging table and lamp heights as you'll need to work on that for balance. Please try this arrangement, and post by commenting and using the Attach Images button to add pix of the update. We'll tweak it on out from there.

Perhaps a large round table might mean a rug is not at all necessary. It could be a metal tray table, or carved wood like Rebecca Mitchell Interiors illustrates. Ideas also to consider, using multiple tables can be found at http://www.houzz.com/multiple-coffee-tables. I also agree with comments above that some color is needed on the walls. You could then hang round mirrors, or an unusual curved shape like RMI shows above.

First of all, I don't think that furniture is comfortable enough to sit and watch TV, so the TV should be remove from that room, the purple wall paper and the purple furniture is too much, you should consider another color for that wall and the furniture against the wall it doesn't look good. What is that room at the end is kind of dark and I cannot appreciate exactly what is the purpose of that room. I'm a firm believer in skylights, we have skylights in the laundry room, kitchen, living room and office, they make a big difference. (if you cannot have skylights (or tube lights) can lights are a great option. There are a lot of great ideas from everyone. I can't wait to see the after photos.