I notice certain sites, such as about.com, that don't show the "Ads by Google" link, and have a different look than the normal Adsense ad's we "regular publishers" are capable of delivering, such as different font's and sizes.
These ad's are much more appealing to me.
I'd love to be able to change the font, and the ad's be more customizable than the choices we currently have.
This would probably help everyone's CTR, since people are probably getting used to seeing the "standard" Adsense ad, and are becoming blind to them. (They're on just about every other site.)
Do you have to have a certain amount of monthly page impressions, to be able to have "personalized-to-your-site" Adsense ad's?