Valve has added a new option to Steam, allowing users to permanently delete games and other purchases from their library.
VG247 points to the new feature – perhaps a welcome sight to those who have made questionable purchases during discount promotions, or received a joke gift from someone on their friends list.
Games purchased as part of bundles both on our outside of Steam (such as Humble Bundles) can't be deleted individually. Instead, each game included in the package has to be removed – or none at all.
Performing the action on any given product doesn't result in a refund for it. It's also worth pointing out Valve's service already offers a less permanent, seemingly just as effective option in its hide feature – which puts any given product into a category effectively invisible to the owner.

http://www.mcvuk.com/news/read/steam...-games/0160056