Below are the ones generally used:
sbl.spamhaus.org
relays.ordb.org
virus.rbl.msrbl.net
phishing.rbl.msrbl.net
dnsbl.njabl.org
dynablock.njabl.org(nor used mostly, right now only mail1 uses it)
spamcop has become too agressive to be used as RBL as they say by themselves.