What do you look for in a theme?

I was wondering what you look for when looking for a theme, either for use with a client or personally?

The overall design and how easily it can be edited. I usually purchase a theme for a piece I would like to use from it, or to see how something was done. I like to change it as much as possible, or simply use things from it in another project.

Clean coding – this isn’t much of a problem here due to the review process.

Uniqueness (is that even a word?)