The go to place for my digital games! Honestly never had any issues with CDKeys - you get the codes within seconds of purchase and then go and redeem on the relevant store (I have just bought XBOX codes but i'm sure there wouldn't be problems with any other system either).
Prices are always very good, usually cheaper then digital versions on Amazon, and definitely cheaper than on the official stores - and they always make it clear exactly what is included in each version of a game (when you have "Standard", "Expanded","Ultimate","Special Edition" versions of games it can get very confusing!) so you can easily choose based on what you want.
Highly recommended