you know what would REALLY piss them off? sell them the game for a hat, whatever 1.33 hat, they will regret it :D

also, put in there revelations 2012

Garry Newman had a flood of Bad Rats gifted to his steam inventory apparently.

The last game I won.

Bat Rats

Dwarvfs!?
http://store.steampowered.com/app/35480/

hmmm, giving someone a game does not come close to being a prank, regardless of it being terrible.

Magic Crystal is great, Ponies ftw!

The Graveyard, of course.

World Basketball Manager 2010

a BL2 key from GamersGate

You need to have OCD to be bothered about a game in your library. I have tons of crap in mine and it's neither in the way or a nuisance of any kind. +1 for my collection count, GG.

Call of Duty games. Blargh...

War Z

Super meatboy! Hate that fucking game!!

Steam Community Beta Access - it's giftable.
But if you want real game, I'd go with Nation Red.

FORTIX

Skyrim

I want secrets of the magic crystal please :D

The Graveyard.
My friend tried to send this game nultiple times as a gift and i denied it every time.

Children of the Nile: Alexandria :3

Trauma

I would be happy with a copy of Bad Rats. Just sayin'.

Dota 2?