I'm in the process of testing about 200 directories to see which ones register as backlinks. If it registers as a backlink to the listing page, it will pass PR. Unfortunately, the vast majority of new directories have a low PR or a PR of zero, or they may have a home page PR of 8, but inner pages PRs of 0 to 2.
IMO, PR is currently overrated. Google has substantially devalued it with the recent updates. A year ago it was "all powerful", but several Google reps have recently stated that it is "only one factor out of a hundred" that they use for ranking.
I still think a good PR link gives a new site a boost and starts sending googlebot more often, but all it takes to get a PR of 5 is to have one single PR 6 site link to you, and that will not rocket your site to the top of the rankings.
Most of my clients with #1 or #2 positions for their most competitive keyword phrases have never had a PR greater than 5.
BTW, all the sites on the list I provided above do show up as backlinks. The Strongest Links list provided by Intensity is also considered to be a very good directory list.