oh, you have Posts: 2,607 I think you should have known it According to my experience, if your sites have quality traffics, 160*600 ad unit performs well.
Whoa, that is a loaded question!!! The site design with the highest CTR is one that hides the real content from the view (lots of different ways to do so) and only shows the Adsense ads. Whether or not Google will let you get away with it for very long is another matter. Check out this thread ... forums.digitalpoint.com/showthread.php?t=293633 Phil G