You have to use this voucher:
WINTR-SRVEY-42012
It works on top of any current sales and works on pre-orders. Only one per account, however, if you use it on selected pre-orders, they give you another 35% off voucher to use on any game.
http://www.greenmangaming.com/
Also, here's a 25% off voucher:
GMG25-CZPYL-D5MQ6
Not sure if it works on top of the 35% one, didn't try it out, if it does, then I just wasted a bunch of money. However, this one can be used if you already used the 35% one (although creating another account would work as well, don't really know if they track by IP or whatever).
WINTR-SRVEY-42012
It works on top of any current sales and works on pre-orders. Only one per account, however, if you use it on selected pre-orders, they give you another 35% off voucher to use on any game.
http://www.greenmangaming.com/
Also, here's a 25% off voucher:
GMG25-CZPYL-D5MQ6
Not sure if it works on top of the 35% one, didn't try it out, if it does, then I just wasted a bunch of money. However, this one can be used if you already used the 35% one (although creating another account would work as well, don't really know if they track by IP or whatever).
Almost grabbed Sniper: GW 2 but I'll wait for reviews.