Rekt1337

I'm suggesting you consider Ryzen. Depending on pricing you may be able to get a generally more powerful system for the same price. While Intel wins most current gaming benchmarks, more AI heavy titles do better with higher core counts. Also the actual difference in most titles is close to imperceptible. Which you should choose is really a matter of relative costs.
 

It really comes down to pricing. As you say, you don't want to cheap out on other parts of the system. You have a decent idea of what you want and what the tradeoffs are. It's just a matter of being patient then working out the relative costs of the builds. 
 
I do think that it is a matter of assembling comparable builds then looking at the costs. If the 2700 is not at least 5% less expensive, assuming all other components are the same, I'd probably go with the i5-8600K.

Ryzen is excellent value, but if you can afford the i5 It's better. Just know the motherboards are more expensive, sine you'll need a Z370 or Z390 board to overclock. With Ryzen, you'll get to use a B450 board and save some more cash, which you can spend on faster ram, which will boost Ryzen's CPU performance.

with your current gpu i would say (as much as i love ryzen) it would be better to go with the i5 8600k as even linus said that its a very good gaming processor

Hmm, yeah ram prices are still bad even for DDR3. In theory you should not mix and match but unless you are doing heavy memory work then you should be fine.
 
You can buy a random 8GB stick as long it's 1600mhz DDR3 and it will 99.9% be seen as 16GB in total.
 
 
 
Hope this helps!

as long as they don't operate on the same channel you will always be good.
 

I just don't know.  I'd like to think that the 1080 will drop to $400 and the 1080Ti will be $600.  Will they?  No damn idea.
 
If the 1170 (?) comes out, it should be roughly the 1080 performance.  Will they price it at $400 like the 1070 (name sake pricing)?  Or $500 like the 1080 usually is (performance pricing)?
 
I would wager we all should grab some lube, cuz they're most likely going to screw us.
 
TLDR:  Buy the 1080 for $450, now. Use it, enjoy it, love it, game like a motherf*cker
 

It's not quite that simple, IMO.  You're rig isn't bad, it's just aging.  If you want to spread out the funds a bit, get the GPU now and enjoy it.  It'll definitely give you alot more FPS than you're getting now.  Then upgrade the rest later.  

Either way isn't right or wrong, just depends on what you want to accomplish when.

If you want to build a whole new rig now get this, otherwise just get the new GPU and another 8GB of RAM and then jump to a DDR4 platform when you have the money
 
PCPartPicker part list: https://pcpartpicker.com/list/Kfd4Bb
Price breakdown by merchant: https://pcpartpicker.com/list/Kfd4Bb/by_merchant/
CPU: AMD - Ryzen 5 2600 3.4GHz 6-Core Processor  ($165.99 @ Walmart)
CPU Cooler: ARCTIC - Freezer 33 eSports ONE (Black/White) CPU Cooler  ($32.28 @ Newegg) // @seoz //
Motherboard: Asus - STRIX B350-F GAMING ATX AM4 Motherboard  ($113.96 @ Amazon)
Memory: Corsair - Vengeance LPX 16GB (2 x 8GB) DDR4-3000 Memory  ($159.99 @ Amazon)
Storage: Samsung - 860 Evo 250GB 2.5" Solid State Drive  (Purchased For $0.00)
Storage: Seagate - Barracuda 2TB 3.5" 7200RPM Internal Hard Drive  (Purchased For $0.00)
Video Card: EVGA - GeForce GTX 1080 8GB ACX 3.0 Video Card  ($454.98 @ Newegg Business)
Case: Fractal Design - Meshify C TG ATX Mid Tower Case  ($101.98 @ Newegg Business)
Power Supply: SeaSonic - FOCUS Plus Gold 650W 80+ Gold Certified Fully-Modular ATX Power Supply  ($69.99 @ Newegg)
Case Fan: Corsair - ML140 97.0 CFM  140mm Fans  ($35.83 @ OutletPC)
Total: $1135.00
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-08-08 14:05 EDT-0400

You're at the lower end spectrum when it comes to just dropping in a high end GPU for 1440p+ gaming.  If you can move fast, I'd grab the Gigabyte 1080 on Newegg for $449, another 8GB RAM and see where it lands you.
 
It's what I would do if I had budget constraints.  If have no constraints, I'd do what I did in my sig.  
 
I'm on the fence really.  You can't OC that CPU and I'm concerned how it would fare in a 1440p+ situation even tho you'd be using more GPU.
 
Yeah, get a good deal on a high end GPU and enjoy that for a bit.  Then think about upgrading the rest when Intel's new stuff breaks, you'll be able to make a good decision on Intel or AMD current of previous gen then.
 
Edit:  I don't want to really push you either way without knowing your available funds.