Usenet-Crawler - Usenet-Crawler is a usenet indexing site helping you to quickly download nzbs.
drunkenslug.com - Usenet indexer providing SSL and integration for Couch Potato, Sonarr, Sabnzd and more.
Newzleech - Usenet binaries search engine with NZB
NZBHydra2 - NZBHydra2 is a meta search for NZB indexers.
DogNZB - A newznab based Usenet newsgroups indexer. Access by invite only.
NZBClub - NZBClub index Usenet automatically almost real-time and make it available for NZB search.