HBO is the original Halo community, older than Halo: CE itself, run by community legend Louis Wu.
ForgeHub is the home for Forge discussion and creations. If you enjoy forging more than fragging, this is your home.
Halo Waypoint is the home of 343 Industries and the official destination for all Halo news.
Podtacular is the long-running podcast covering the entire Halo franchise.
Rooster Teeth is one of the biggest names in web comedy. They are the creators of Red vs Blue, Achievement Hunter, RTX, and Grifball.
The Halo subreddit is a large community of Halo fans of all stripes: Competitive, casual, lore fans, and more.