This is my gaming PC. I've tinkered with it for about 6 months now and it's now where I want it to be. My goal was to build a quiet, powerful gaming rig capable of 1080p gaming at max settings in every game while not having to spend 4-5k on parts. This is close, very close. The CPU is overclocked to 4.2 GHZ and kept nicely cool and quiet by the Corsair H100i and 2 120mm beQuiet fans. I replaced all of the Air 540's case fans with beQuiet Pure Wings 2 fans. They all offer great airflow with minimal noise and don't break the bank like Noctuas. Also, they're all black, which is what I wanted, something Noctua does not offer apparently.
The video card is the noisiest component in the system. While I wanted to get an Asus Strix 970, they were not available when I was ordering so I settled for the Gigabyte G1 gaming. While it's a great card, the noise level is a bit high under load. It's a compromise I can deal with though as I mainly use my headset while gaming anyway.
My favorite part of the build is the case. The Corsair Air 540 is an amazing case to work with and build in. Cable management could not be easier and the amount of airflow across your parts is awesome. I have two 140mm intake fans in the front, one 140mm intake in the back and two 120mm exhaust mounted to the Corsair H100i radiator. All are controlled by Asus' AI Suite 3 software for minimal noise. The only downside to this config is warmer air flowing through your radiator, however temps on the CPU only reach around 60c under full load and overclocked.