Well perhaps not really ‘The Ultimate’ but certainly the interesting one. It is far more geared towards helping you to manage your Google AdWords campaign (or basically steal your competitors one!), but has an interesting SEO Ranking report as well.
Their SEO ranking tool is missing the Internationalisation that they support quite well in the Payd Keywords analysis, and that is the major drawback on the usage for of the KeywordSpy for the International search engine optimisation.
This is what the KeywordSpy marketing blob says about themselves:
Find which keywords your competitors are using!
Increase your Ad Campaign revenue by finding the most profitable keywords.
Get access to over a billion keywords in our database.
KeywordSpy is certainly the one to keep an eye at, since they are adding new and interesting features fast as well.
Google PageRank (PR) Update - SEO Consultant down to PR 4