Although all of members here go in favor or go against but for me it even can't compared. All of you comparing two rivals i.e Google and MSN. Google has nothing to do with Alexa and in the same way Alexa has nothing to do with Google. If you think Alexa stats are compiled from traffic only then you are wrong. Alexa counts everything just like Google's
PR but
PR is very complex formula. It is rather difficult to get listed in Google but MSN doesn't behave in this way. On many forums I have read that MSN admires new sites and list them high but someone will has to maintain it hardly.
SO there is no comparison between Alexa and Google's
PR.