I found this reference to Strongest Directories from Directory Aviva. The Directory tires to answer the question of "what directories should I submit my site link to"?

"…Fortunately, the folks over at Seomoz have recently developed a page strength tool.  While it also looks at .edu and .gov links, it takes a much more holistic view of the website than ILQ does, and probably is more representative of how Google views websites (and directories).

According to Seomoz, the page strength tool is “a better metric to quickly assess a site / page’s relative importance and visibility.”

AFAIK, no one has comprehensively applied this tool to the directory space, so I’ve gone ahead and done this.  I’ve checked the page strength of all the paid directories listed in Bob Mutch’s comprehensive listing and then ranked them in order of page strength.  (If you would like your directory added to this list, please contact me - there’s no charge for this).

The list was last updated about a month ago - I'll highlight the one's I think might be interesting to submit to that I've not been aware of till now:

"…Without further ado, below are the strongest directories (last full updated January 31, 2007:

Page Strength 10
http://dmoz.org/ (free)
http://dir.yahoo.com ($299 per year) (Directory sub domain has page strength of 9.5)

Page Strength 9
http://www.business.com/ ($199 per year)

Page Strength 8.5
http://www.stpt.com/directory/ ($99 per year) (Directory folder has page strength of 6.5)

Page Strength 8
http://botw.org/ ($149.95)
http://bubl.ac.uk/

Page Strength 7.5
http://www.joeant.com/ ($39.99)
http://directory.v7n.com ($49.95) (Directory sub domain has page strength of 6)

Page Strength 7
http://www.2yi.net/ ($9.95 / $29.95 per year)
http://www.alivedirectory.com/ ($34.95 / $74.95)
http://www.avivadirectory.com/ ($34.95 / $74.95)
http://www.relmaxtop.com/ ($20 per month)
http://www.sevenseek.com/ ($40 / $99.95)
http://www.uncoverthenet.com/ ($39 / $199 per year)

Page Strength 6.5
http://www.chiff.com/ ($59.95 per year)
http://www.elib.org/ (50 Euro)
http://www.gimpsy.com/ ($40)
http://www.goguides.org/ ($39.99 / $69.95)
http://www.greatnexus.com/directory/ (n/a) (directory folder has page strength 5)
http://www.haabaa.com/ (#30 / #50)
http://www.skaffe.com/ ($44.99)
http://directory.sootle.com ($19.99) (directory sub domain has page strength of 6.5)
http://www.tygo.com/dir ($39.99) (directory folder has page strength 6)
http://www.wowdirectory.com/ ($35 / $55 per year)

Page Strength 6
http://www.blogtagstic.com/ ($9.97 / $29.97)
http://www.directorydump.com/ ($34.99 / $49.99)
http://www.ezilon.com/ (free / $49)
http://www.familyfriendlysites.com/ ($4.95 per year + recip / $49.95 per year + recip)
http://www.gii.in/ ($25 / $50)
http://www.goongee.com/ ($19.99)
http://www.kwikgoblin.com/ ($24.95 / $49.95)
http://www.mozdex.com/directory/ ($29.95 / $49.95) (directory folder has page strength 5)
http://www.qango.com/ ($50)
http://www.search4i.com/ ($15 per year / $25 per year)
http://www.uksmallbusinessdirectory.co.uk/ (30 pounds / 50 pounds)
http://www.umdum.com/ ($40 / $99.95)
http://www.vxbox.com/ ($3)
http://www.webworldindex.com/ ($25)

uote>

There's more but I did not include any link lower than a PR=5.