Fanatical

I am their client since January 2014. I have purchased dozens of bundles here as well as joining some of their special offers ("Star deal").
Key collection is instantaneous and, in case of problems, support is friendly and helpful.

Why did not I give 5 stars?

Some games are now repeated too many times in their bundles, making them unattractive. They also succumbed to the "mistery games" ̶s̶w̶i̶n̶d̶l̶e̶ business model.

I bought a couple of bundles from this store a while back, never encountered any problems. Prices for games that are bundled are generally pretty good, however their store prices are nothing special (didn't notice anything significantly lower than what is there on other stores).

One downside I could say is that lately the newer bundles haven't brought much to the table, it's mostly limited to indie games and alike, while in the past there were more quality games in their bundles.

Its great website to buy games from and already I bought 4 games from them and it will be my primary source for games.