Pre-purchase either Dead Island: Riptide, Aliens: Colonial Marines, Tomb Raider, Metro: Last Light, Bioshock Infinite and a bunch of other upcoming games: http://www.greenmangaming.com/coming-soon/
Use this voucher to get 30% off on that purchase: GMG30-DEC01-ARFC9*
Then you get a 35% voucher which can be used on another game. Though it seems it'll expire after 21 days of that pre-purchase.
Tomb Raider €31,50 (after discount) + Metro: Last Light €32,49 (after discount) = €64
And no, I'm not affiliated with GMG. Do I need to be to mention an awesome deal? I'm certainly considering it.
*Though it seems that 30% can't be used on Infinite. Infinite still has that cash-back deal it seems. I much more prefer vouchers myself, honestly.