idolw - 7:29 am on Mar 15, 2010 (gmt 0)
I only look at Alexa these days. This is not perfect but it more or less shows me whether I can get traffic from a site or not. Google taught me to go after links delivering traffic - these help the most both: traffic and rankings.
Truth is: high PR sites usually have high traffic but I know a handful of PR5 and 6 sites being penalized.