I bought Wolfenstein (the new colossus & the new order) through Kinguin a couple days ago, and I'm incredibly happy I did so. The keys were delivered within a couple of minutes (including payment time) and were perfectly valid.
I had (regrettably) earlier tried to buy the same games from G2A a few hours earlier, where my payment wouldn't even go through. Even if it had, Ive had problems with G2A before, and it was not unlikely the seller would even give me a legitimate key.
Couldn't recommend Kinguin more, and I look forward to buying through them in the future :D