So I'm planning to get myself entirely new pc (only thing I can really reuse from old one is psu).It's gonna be mainly gaming build and I would really like for it to be somewhat "future-proof" one

The main 3 scenarios are:
1)build with i7-7700k &gtx1070,
2)build with i5-7600k & gtx 1080,
3)build with Ryzen 1700 & gtx 1070

All 3 builds have their good and bad sides with Ryzen possibly being better choice long term than 4 core intel (though it's only a guess)
On other hand i5 and i7 are well know quantity and offer better (i7) or really close performence at this moment, and then there is i5 build which allows me to get better gpu,

so yeah I'm really thorn between all of them :fire

 

yeah it's really interesting architecture though atm. games just lack optimization for 8 cores,mafia 3 is only benchmark I've seen were 8 core cpus like 6900k or Ryzen 7 pull ahead of 4 cores like i7-7700k.
or i5-7600k.
Though it is likely that games will start slowly move to 8 core optimization in 2017 it's not guaranteed which only adds to my dillema

 

Also keep in mind that pretty much all developers used Intel platforms to develop games for the last few years, since AMD was pretty shit. So some optimization for the AM4 platform on the devs part may also help. There's also still some kinks to be worked out with the UEFI/BIOS of the motherboards, and you currently need some specific RAM (single rank, not dual rank and only up to 2600MHz) otherwise things can get weird.

Anyways, most important thing in a gaming build, more often than not, is the GPU, so go for the build with the 1080. Except if you're playing very CPU heavy games, like Arma 3 for example, then go for a good single core performance CPU and the 1070. And out of curiosity, complete name of the PSU you want to continue using, as well as its age?

 

it's xfx core ts 550w not even year old and cleaned every 2 weeks
http://www.xfxforce.com/en-us/products/ts-series-bronze-full-wired/ts-series-550w-psu-p1-550s-gren so it should be in good condition.
good cpu would be useful for me as I emulate a lot and stuff like citra(3ds) or rpcs3(ps3) is getting better beside that I play mainly rpgs like witcher3 or some occasional shooters (overwatch mainly)

 

What resolution are you gonna play? If its 1080p than i7 option is the best. I play 1080p duo to my 144hz 1080p benq and games I play are cpu heavy so if you are like me its 1 option. 7700k is outclasting even cpu like 6900k in 1080p gaming, mostly duo that games do not utalize good multiply cores and big clock speed means a lot. That why 7700k is just outshinig other cpu in this benchmarks and 1070 is more than enough for 1080p. You have to ask yourself what games you gonna play and on that resolution(if >1080p buy 1080 if not than 1070) if you are not in hurry I would wait for razyen 5 which will be competing with consumer i7 and i5. It will have probably much better performance with it higer clock speed, its also good to wait for Vega as nVidia is little bit scared right now after razyen.

 

hmm I'm gaming at 1080p atm but if I got gtx 1080 then I would probably try to get 1440p monitor next year.
Yeah waiting for Vega would be smart thing to do but I already took loan
so I'll be buying new rig probably this weekend.

 

A 1080 is overkill for most 1440p games and is really only worth it if you're interested in 4k @60fps.

 

I don't know what gave you that idea, but if you take a look at some benchmarks you'll realise that what you're saying is wrong.

 

Yeah, it's not like any of your proposed systems are bad.

Although for my own personal needs I would choose a Ryzen system, I think one of the Intel systems might be the best fit for you just because they're the best performing for gaming now and there's a decent chance those Intel cpus will still be better at gaming than the Ryzen in the future.

 

Go with an i5 instead of an i7. They're overhyped.