Aside from the obvious ones; static pages, non spam websites, pagerank, alexa rank, etc. etc. etc. what type of features do you look for in a directory. For example, i'm talking about features. So maybe you want a directory that will feature you website, maybe one that will provide traffic stats for how many clicks your link gets, maybe you want a directory that lists you regionally and also by category, etc. etc. Try to stay away from the typical more general responses.