Lichess.org: Free and fast site that allows you to play anonymously. Hourly tournaments if you make an account. Can also play variants, including Crazyhouse, Chess960, King of the Hill, Three-check, Antichess, Atomic, and Horde.
Chess.com: Large site with many players. Can have a free account, but you won't get many features without a premium account.
Kingscrusher - Youtube channel of a FIDE titled CM from the UK, has many interesting and exciting analyzed games played by GM's on his channel. He also occasionally streams live play and analysis on Twitch.