I like to keep track of the things I do, even the things I do for fun. That way, when I start thinking "I haven't even done anything this week!" I can look back and say, "well, at least I read three books this summer." That's what Goodreads is for. Now, there exists a similar site for video games, which I just found out about, called The Backloggery.
You can keep track of what games you have and which ones you've beat, and you can follow what games your friends are playing. Neat, huh? Currently it allows reviews and various completion categories. However, there are a few things it lacks before it reaches Goodreads's level of awesome (still, it's an impressive site, given that it's one coder's side project):
-A catalog of games to search from and add from. Maybe they could team up with mobygames or the Sisimizi catalog for a start. With the games cataloged, it would reduce title typos and allow tracking of how many people own the game. It would also let users see other reviews of the game.
-Partnerships with game companies to enter users in giveaways. Seems like a good way to sponsor getting the cataloging stuff done.
That said, it does a few things better than goodreads. It shows system stats, like how many registered unfinished games there are by console, etc. It also allows reasonable customization of one's profile page and display defaults. Sure, by not resizing your banner automatically it makes it less user-friendly, but it also allows more freedom to make a banner that isn't the exact same size as everyone else's. And for the most part, it looks like users have good taste (not too many animated gifs).
I think it's a great idea, and I think it will probably get more popular as time goes on. Let me know if you decide to join--I'm signed up as Whistler.