It's surprising that nobody thought of this before: Blender-Games aims to offer all completed Blender games, complete with graphics and videos. It's very nicely designed and already has a lot of great content.
Here at blender-games we are posting most, if not all, completed blender games, so that you don't have to search through Google and BlenderArtist.org to find them (or any other site)! You can talk all about the games in the forums, upload your own screenshots and videos, and post your own games!
We are looking to build a community, so if you are interested, please stop by and register for free and upload your content, post on forums, post free low poly downloads, post games (read the guide!) and help shape this new site.