Green Man Gaming (GMG) has put out a new voucher code good for 25% off any unreleased game at their store. Unfortunately, there’s no easy way to find out just what’s available for pre-order.
The voucher code is: CUSTO-MERLO-YALTY
So far the games I’ve found that it works on are:
Update: This is their list of upcoming games (for your region). Europe has Mass Effect 3 for €31.71 for example.