SEOMoz recently released a new page strength tool called Trifecta. I used that to build the web's top blog directories list by strength. What I found most interesting as I stated on the page itself was that the first page of the SERP's were some of the lowest scoring on the list. Search "blog directory" on google and look what comes up. Hopefully this will assist some people when choosing which blog directories are worth a submission. All the best,