Nitin You can go with white sectional sofa with very low Back, very sleek rest arms will make the room appear bigger. Also the TV go for LED or plasma mounting on wall so the space will be saved. If you can have pot lights LED with dimmers will make the room look totally different.
Rachana Jhunjhunwala Yea I am also thinking in the same way Nitin. TV is already on the wall. Please see the other picture. but no white....I love white color but too much of care....Give some more Ideas with picture.
ASVInteriors Probably an arrangement of two sofas, two armchairs and two poufs set around could work. Pottery barn.com, crateandbarrel.com, westelm.com do good quality and value furniture.
JWinteriors I've attached a great window treatment idea for the bank of windows. A sectional would give maximum seating with a side chair for conversation. Get a highboy for under the TV. There shouldn't be much distance between TV and the furniture piece. This is assuming you don't wish to have a built in cabinetry with a wall mount fireplace below...oooh! Get a significant coffee table with either a shag rug for texture or a rug of many colors to anchor the space. Don't forget task lighting with lamps. Stay away from touchiers.
This may compliment your style.