IGDB - An open video game database
Ninja Kiwi - Ninja Kiwi, creators of awesome free online games.
FreeToGame - Your digital game store where everything is free!
Armor Games - Play free online games at Armor Games! We're the best online games website, featuring shooting games, puzzle games, strategy games, war games, and much more...
The Visual Novel Database - VNDB.org strives to be a comprehensive database for information about visual novels.
Kongregate - Kongregate has free games that you can play online. Choose from thousands of free flash games.