IGDB - An open video game database
Board Game Arena - The largest board game table in the world. No download, directly from your web browser.
FreeToGame - Your digital game store where everything is free!
Battlegrounds Gaming Engine - Play digital versions of boardgames, wargames, card games, or dice games.
The Visual Novel Database - VNDB.org strives to be a comprehensive database for information about visual novels.
Tabletopia - Online sandbox arena for playing board games just like in real life.