Just found this great site, via RPS [ http://www.rockpapershotgun.com/2011/04/18/shelf-life-darkadia/ ], that let's you display all the games you've ever owned on a virtual shelf.
Here's the link - http://www.darkadia.com/
It's simple, it's quick and best of all - it uses the Giant Bomb database - so you can add everything from indies like Desktop Dungeons or Machinarium to Mass Effect and Final Fantasy MCMXCIC-2. There's probably three decades worth of games in the database.
Check the links and the site's faq page for more info. Took me around 20-30 minutes to get my library/shelf together. I won't be linking it though, since it's pretty shambolic. :p