Don't forget Humble Bundle, Bundle Stars, GoG.com, Green Man Gaming, Gamersgate, Steam, uPlay, Origin, G2A.com, Direct2Drive, Desura, Amazon... And there are a heap of key sites too.
Don't ever buy a game at full price. ;)
Keep an eye on:
www.thefreebundle.com
www.origin.com/en-au/store/free-games/on-the-house
http://forums.steampowered.com/forums/showthread.php?t=851573
https://club.ubisoft.com/en-US/welcome
For free games.
--::{PC Gaming Master Race}::--