There probably is no best. Most adsense optimized wp themes I've seen still suffer from the number one problem all wordpress themes face with regard to adsense and that problem is that there are WAY to many OTHER places for them to click besides the adsense ads.

Three column sites give the visitor too much to look at and get distracted by. For me two columns perform much better.

You should have minimal real links to suck them into your site.

Then there are some wp themes such as bluesense which have so many ad blocks they violate G's terms. I generally avoid WP if I'm making an MFA because mine are like George Foreman's grill. Set it and forget it. I don't want to go back to apply the steady stream of patches no matter how easy it is. It isn't easy if you have 200 domains. And after you have 200 unpatched domains, they'll get hacked, the adsense publisher id will probably have changed and you'll be linking to the 3p's, porn, pills and poker and get your adsense account smart priced and your pages dropped form the index. Other than that I think WP is the cats meow.

The best one I have found is called Heatmap. Do a Search on it within Wordpress and you'll find it or on Google. I just started using it and I love it. Stuart is the designer and is very helpful.