It's the first time I've rendered using day light and the result is impressive. Sunlight makes things look real than normal lights and white light source.
I set the time at 11 am, and let the window face directly to the sun (East).

Notice the compass


Final render (3000x1688)


Download link
http://www.mediafire.com/download/dvwia93qdqixmab/4.png

Hope you try sun light to experience different results.