There are some clear elements that make a good one wordpress theme, or very good. Next I present some personal opinions about things that a wordpress theme would need to have.
1. a simple, easy to understand, intuitive design
2. code must be impeccable, as simple, without flourishes (js, flash, etc.)
3. SEO must be implemented properly (no random h1, h2 tags)
4. ideally have commercial spaces (adsense)
5. the “theme options” would need to be able to handle as many things and this has to be simple.
6. Cross-browser compatibility – this is the biggest problem (especially in IE)
I will complete the list, as you inform me. Please do not hesitate to comment.
In the next posts I will try to elaborate each of the points above