Got invited to play the beta of Titanfall and after my first few games I felt like purchasing it. Simplified mechwarrior + FPS… How can you argue?
Out of the few CD key sites I goto I found gaming dragons to be the cheapest.
Titanfall @ $41.58 http://www.gamingdragons.com/en/game/buy-titanfall-origin-ke…
Use code "GMD-FTW-5OFF" for discount at checkout.
Other big titles for PC that I saw were also:
Thief (Steam) @ $29.99 http://www.gamingdragons.com/en/game/buy-thief-2013-steam-cd…
Diablo 3 - Reaper of Souls @ $39.99 http://www.gamingdragons.com/en/game/buy-diablo-iii-reaper-o…
EDIT: I should mention it is USD.
EDIT2: Even cheaper thanks to Motordom for discount code "GMD-FTW-5OFF"
Using this method, you can get Titanfall for approximately $42USD. Requires a little more effort, but you do get a saving.