Here are commercial services that might be of interest to SEO professionals:
SEMRush.com was designed by the developers of SeoDigger and SeoQuake for Google organic and AdWords keywords research.
Wordtracker helps website owners and search engine marketers identify keywords and phrases that are relevant to their or their client's business and most likely to be used as queries by search engine visitors. Marketers can also determine how many competing sites are using those keywords and can identify the phrases that have the greatest traffic potential.
The original "Best of the Web" got its start in 1994 when Brandon Plewe, then a student at State University of New York, Buffalo, created a platform enabling the burgeoning online community to nominate and vote for best-of-class websites in a variety of categories. From the initial concept of Web Awards, Best of the Web transformed into a comprehensive directory categorizing content-rich, well designed websites.
BuiltWith® is a website profiler, lead generation, competitive analysis and business intelligence tool providing technology adoption, ecommerce data and usage analytics for the internet.