The fine folk at StudioPress have this to say about Genesis:
And we concur.
Genesis Themes provide you with high quality designs, already lightweight, SEO optimized and secure. We looked long and hard before we chose Genesis, and we’re confident that we made the right choice.
Aside from the SEO and the security – we think Genesis offers a nice range of designs – so that you should be able to find one that will suit your business without much trouble. Genesis is extensible too – you can work with one of our approved designers to create a design specifically for you.