My rig was built over the course of the last year and a half, and finally is in what I'd consider to be its final form before my next big upgrade in the next two years.
I chose the Intel i7 7700k since when the build started it was the fastest processor for single threaded workflows such as gaming which is my primary focus. It's also readily compatible with MacOS in a hackintosh setting which was another big plus. In addition good overclocking performance was a big plus. I had it professionally delidded by Silicon Lottery which aided in cooling and allows me to readily and stable-ly hold 5GHz at 1.34v (this voltage is conservative for stability in some stubborn games such as The Division, it was stable in most titles and all the stress tests I used at 1.32v). It's being cooled by the Corsair H100i v2 240mm AIO and doesn't reach above 75C maximum temperature and typically runs around 60-65 in games. It's being fed by my Corsair Vengeance LPX DDR4 at 3733MHz and CL17 timings.
I paired the 7700k with the Aorus Z270X Gaming K7 since I like the heatsink covers and the LED effects and I had heard good things about Aorus from some reviews. The VRM is also a high point for this build since it can hold the voltage well. Unfortunately, for as nice as the hardware itself is the software sucks. The LED software caused major stuttering in Overwatch and minor hitching on the desktop. You can control the color of LEDs on the board from the BIOS but you have to reboot to make the change so it's hardly worth it since the software is so unusable. That goes for the fans portion as well, they market SmartFan 5 a lot but I set my curves in BIOS and left them until finding my workarounds for the LEDs/Fans.
Speaking of which the workarounds used were the purchase of an NZXT Hue+ for lighting effects rather than attaching a strip to the motherboard (which also allowed more flexibility) and a Corsair Commander Pro for the fan control. I'd probably go full Corsair next time around for the ease of using one manufacturer's ecosystem and because while neither software is particularly great, Corsair's is a step up from NZXT's Cam. The Commander is possibly one of the highlights of my build to me, it's a huge benefit to be able to program fan curves and switch profiles so my PC can be whisper quiet when I'm not gaming.
My GPU choice was obvious, I picked up an EVGA 1080ti SC before the crazy price spike last summer and have been loving it ever since. Unfortunately the cooling was a bit of an issue so I purchased an NZXT Kraken G12 bracket and a Corsair H105 240mm AIO to help with temperatures. My case, the Fractal Design Meshify C TG fits both AIOs and has a nice PSU basement which helps with cable management.
My PSU choice was the Corsair RM850i 850w smart PSU which gives me wattage options in case I choose to go SLI rather than upgrade the 1080ti when the next generation Nvidia GPUs are released.
Finally for Storage I've got the OCZ RD400 256GB NVMe SSD for my Windows 10 boot disk, an ADATA 240GB SATA SSD for my Mac OS 10.12 boot disk, and 2TB Seagate Barracude and 6TB Seagate Ironwolf HDs for mass storage.