RBLs in use

I have been asked to find out what DNSBLs are in use so my employer can see what the incidence of its being blacklisted is and how much impact this is likely to have had on their business. What DNSBLs are being used by the various agencies represented on NANOG and how much weighting do you give them. Are there any DNSBLs you would completely ignore due to data quality issues? Thanks Paul