system
A chat on subreddit /r/pcmasterrace
human
I guess it depends on if you want a positive or negative pressure case. Honestly I’d have my fans orientated like this in this case because I don’t want fans blowing air from outside the case (with all of its dust and crap) towards my GPU.
gpt
You want it pointed inline with your GPU fan. 

In this case, I would point air inwards, otherwise your making a negative pressure in the space below your GPU, as the GPU fan pulls it's air from there to cool the card.