I use IBP and I swear by it. There is nothing out there as good in my opinion. I have ranked high (top 10) in Yahoo with phrases such as 'iPhone porn', and high in google with phrazes for web-solutions clients, it's truely amazing step by step optimisation and reporting, if you are serious about improving SEO and being a successful webmaster then it's well worth the money.
Get IBP here
Alternatively, if you like, I can provide you 3x detailed 'Top 10' optimisation reports of your site for a small cost of £30 / $50. PM me.
Example:
Report 1: Today, you optimise your site from the report.
Report 2: Next week, you tweak your site optimisation from the new report.
Report 3: Following week, you perfect the optimisation of your site from the newest report.