Area rugs are multifaceted. They can be decorative, functional or both.
Selecting the right rug for you is totally dependent on your needs.

When using an area rug for decorative purpose, select a large rug that will fit in the middle of the room's layout. This works best for living rooms where furniture are positioned for entertainment and conversation. Make sure that the rug is large enough to allow at least 1/3 of the front end of your furniture to rest on it. The style and color you select should be based on the decor of the room. Avoid trying to match colors exactly; this effort is usually useless since different fibers take on color dyes differently. If you have a monotone decor try matching just enough to give the room uniformity. And if using multiple rugs in the room, instead of using the same size and/or pattern, experiment with coordinating colors, styles, sizes and shapes that will add interest to the room.
There is no limit to what can be done when you decorate using area rugs. A living room rug can be one of the most important factors in decorating your living room. The right rug can determine the colors and accents, colors and tones, style of furniture and the overall aesthetics of your living room layout. It can become the center, the main factor that ties the whole room together.