binsearchinfo - https://www.binsearch.info - NZB search engine, one of the largest on the net - also nzb.cc.
BINZB - https://binzb.com - minimalistic but practical, stay away from direct downloads, these forward on the subscription page nzblords
FindNZB - good bye, latest uploads are two years old!
NZBFriends - also good bye, latest uploads are two years old!
NZBIndex - https://www.nzbindex.com - one of the largest NZB search engines, very up to date!