Spamhaus tracks the Internet's worst Spammers, known Spam Gangs and Spam Services, provides realtime anti-spam protection for Internet networks, and works with Law Enforcement Agencies to identify and pursue spammers worldwide.
spamhaus and ordb are the best... I have worked for a few ISP's who used them. They seem to work quite well but can cause issues when there is an open relay with a larger ISP and we would block them. Try an convince an ISP that they have a security hole in their mail server.... easier to pull teeth.