for my site studport.com

1 1024 x 768 55.98%
2 800 x 600 20.15%
3 1280 x 1024 14.46%
4 1600 x 1200 4.36%
5 1152 x 864 3.06%
6 Unknown 1.11%
7 640 x 480 0.73%
8 Other 0.15%

I always make the designs for 800x600