I've been keeping up with Defiance, an mmo for xbox, ps3 and pc, and which has a storyline integrated with a Syfy channel tv series of the same name.
The reason I'm particularly interested is the method of storytelling, where the game events feed into the tv series and vice versa. The first time I saw this method of storytelling was actually in X-Wing with X-Wing: The Official Strategy Guide. On the one hand you were playing a game, and on the other you were reading a book that told your character's story between and during missions. It added so much depth to the X-Wing story, and the feeling of immersion in the world.
More recently we've had The Walking Dead, with very high production qualities on its tv series and the computer game, based in a world that originated with a comic book. The game acts as prequel material for the tv series as far as characterisation goes. We see both Glenn and Hershel chronologically prior to their appearance in the tv series.
For those interested, I've added a few video links below: