After 7 years (built on Feb 2011) I feel that's time to get a new rig. Actually running a P67/2500K but didn't found the need of upgrading till now (here is some posts regardiing my old rig).
 
Actually buying some pieces but still deciding other bits (feel free to critique, add/or swap bits unless bought).
 
- Case: Corsair 750D Airflow edition (tried to locate a black DG-77 but unable to - Spanish dealers are real nasty when dealing with EVGA stuff).
- MB: Asus Maximus X Hero *ordered*.
- CPU: 8700K (Plan to OC) *bought*.
- CPU Cooler: EVGA CLC280 *bought*.
- RAM: G.Skill Trident Z RGB 3200 CAS 14 16Gb.
- GFX: 1060 6Gb (EVGA 6262-KR) *bought*. Managed to snag it awaiting to next-gen chips or finding a suitable card to step-up program.
- SSD: Samsung 960PRO M.2 512Gb *ordered*.
- PSU: Seasonic Focus + 80+ Platinum 550w *ordered*.
 
My idea is to OC it at about 5Ghz and keep it STABLE and the most cool as I could (delidding is an option order to reduce some temps) to keep it the most silent possible.
 
Looking too to add some tasteful RGB lighting to it (some rigs out there can compete with Las Vegas lighting) so fans are planned to be added on case and cooler.. 
 
Photos are promised and tests when assembled.
 
Changelog:
16/02/2018 -> Modified RAM to choose the 16Gb RGB version.
16/02/2018 -> PSU: Seasonic Focus + instead off Super Flower Leadex titanium 550w.

EtherCore
That's a pretty good start. You mentioned RGB. Any reason you wouldn't get the Trident Z RGB? I'm personally not a fan of RGB, but this is some really great looking use of it. 

Saw the Trident Z RGB's and liked it, but feared ending with somewhat 'ricer' look (and is what I don't want to) on new machine.
 
P.D: After seeing the price difference is almost negligible between the plain and the RGB. Pretty sure that I'll end with the RGB ones and 'unlit' them if needed.

mike406
DDR4 is massively overpriced now, you over-payed a lot just so you're aware. I got my Corsair Dominator Platinum 16 GB 3000 MHz ram for $123 last year, it's like a $200 kit now.

 
I Know. But since Z370 doesn't work with DDR2 nor DDR3. I don't have anny other option than buying an overly priced DDR4 memory kit.
 

 
Moving to the Mods Rigs section.

I would like to see pictures of progress or final build. That and a 3dmark score will enter you in the Mods rig give-a-way.