Integrations: SABnzbd, Couchpotato, Sonarr, and other major Usenet software
Retention: 500 days
Over 4 million NZBs in 25 newsgroups
Advanced search for paid users
Updates every 15 minutes
abNZB is a free NZB site, but they also accept donations which allow users to get more desirable features and perks. Aside from higher APIs and daily grabs, their advanced search settings are only available to paying users.