After 13 painful years with 2 pre-builds, 2 netbooks and a somewhat decent ultrabook (without any dedicated graphics, though) I finally managed to build my dream system. I wanted it to be perfect in every aspect, especially aesthetics and I think I succeeded. Here are my reasons for choosing the parts that I finally choose after a 5 month research period:
CPU: Since this is a completely new build, I chose the newest Skylake platform. Gaming rarely benefits from the additional threads of an i7, so i sticked with the i5-6600k which is much cheaper and still overclockable.
CPU-Cooler: I wanted to be the build completely black and white themed, and where possible the white color should dominate. It was not easy finding white cpu-coolers though. I never heard of Enermax before, but the reviews and especially the LEDs convinced me finally to stick with that. Cooler is working great, with 50-55°C on stock load and 70-75°C overclocked load at 4.6 GHz, which I think is still pretty impressive.
Motherboard: This was a tough choice between MSi Z170 Krait-Gaming and Asus Z170-A. Both had one white Z170 board with almost the same specs and price. I took MSi, because my reseller had a 20€ discount coupon on it at the time and MSi had a cashback promotion in which I received additionally 25€ back, saving all in all 45€ - nice!
Memory: This was difficult as well. As far as I know, there seem to be a very small amount of white DDR4 RAM. There is GeiL (even with white LEDs, but quite expensive) and Avexir (which is not available in Germany). I choose Crucial, because it's a good manufacturer afaik and I really like the heat sink form. It's grey, which kinda fits my color scheme as well.
Storage: The SSD in the part list is not exactly the one I have, since PCPartpicker doesn't have it listed. It's a Samsung MZNTE128HMGR 128 GB M.2 SSD out of my Samsung Ativ Book 9 2014 Edition, which I upgraded earlier to 512GB. I had it just lying around, so why not use it? Might switch those two in the future, though. The choice for the main HDD was quite obvious, simple WD Blue 1 TB is enough for starters. I just have 14 games so far. I had an additional old Samsung 300GB HDD lying aroung as well, so I put that it as well.
Video Card: First I considered a GTX 970, as it's the most popular card now and I wanted the PC to be able to play games on the Oculus Rift. I still consider this a minimal requirement, so I told myself, heck, why dont get the best of the best? Of course it's almost double the price, but that's worth the performance boost. Sticking with my color scheme I only found the KFA2 GTX 980 TI HOF Edition and the MSI GTX 980 TI 6GD5T (the rather unknown white Armor x2 Edition). KFA2 was too big (reviews said it took 2,5 slots in height), and since I already had the MSi motherboard, why not take the MSi video card as well?
Case: The only alternative I saw, was the NZXT H440. I choose the S340 because of better cable management options, smaller and simpler design and last but not least smaller price.
PSU:: This was a difficult choice. It was very difficult for me to figure out, how much wattage I needed. After much research I though 650 would be fine (which still is I think, correct me if I'm wrong). Options for me were EVGA with their large lineup and great customer service and Corsair. So you might wonder why I have 750W and the explanation is simply that EVGAs only available PSUs with 650W and 750W were priced almost the same here in Germany at about 125€. You still wonder why it's not a EVGA PSU then? Well, I was a bit close-minded at that moment and didn't even consider any other manufacturer. After I finally did, I discovered Corsair and their RM750i PSU at almost the same price. JonnyGuru has great review for it as well. What convinced me, was the Corsair Link software for checking the currently drawn power, which is a pretty nice feature when you're overclocking and want to know how much head-room you got left.
Case fans: Since the S340 comes with only two fans in the back installed, I looked for additional fans and found the Corsair AF120 even with white LEDs - perfect!
Fan Controller: Motherboard only has 3 connectors for system fans and that would look messy as well. So I came to the conclusion I needed a fan controller. The NZXT Grid+ v2 seems like the best (if not only one) internal fan controller available.
LED Controller: Now that's where the magic happens :D Some fancy RGB-Lighting to round things up, just because why not? It looks awesome(altough I currently have it on white all the time, which is kinda boring)!
And finally black/white sleeved cables from CableMod to give the color theme the final touch.
Building this rig took me 8 hours, mostly because of cable management, which turned out to be very difficult. The room for cables in the bottom of the case turned out to be smaller then I tought, since I used up pretty every feature the case had. I had also issues with the RAM, which just didn't want to work in dual channel but only single in slots 3 and 4. As it turned out, the motherboard doesn't support 2400 MHz RAM in dual channel (not sure if only this particular model or everyone) and the solution was to set the RAM clock speed to 2133 MHz in the Bios.
All in all I'm super happy with how it turned out. I've never seen games running so fluently, didn't even imagine it to be possible. I played Half Life, GTA SA and GTA IV probably at 20 or max 25 fps and didnt know any better. For example GTA V running at over 60fps with ultra settings is just breathtaking for me. And I'm ready for the Oculus Rift just in time :D