ionutenciu

Unless you need hyper-treading you wont need a i7 or Xeon...

I use an i5 and have never came accross a situation where I was losing performance because of it..
I mainly game, youtube, and LTT forum on it though.

Core i5 for sure. I've used mine for gaming, 3D rendering, stress simulations, a whole bunch of stuff and I can't get anywhere near the limit.

Those sound like reasonable timelines more or less.  I look at it this way: is the i5 going to do as well in every current game?  Yeah, I believe so.  Will that trend continue?  Maybe, but no one knows.  I kind of hope 2 or 3 years from now tops we will start to see a benefit to i7's and above, but it might not happen.
 
I've got an i7 because I do more than just games, and in hindsight, I would have actually been much better off with an overclocked 6 or 8 core, but A ) that's a lot more expensive, and B ) If I had had the luck with a 6 or 8 core that I did with my i7, I would be really mad since overclocking an i7 is nice, but overclocking a 6 or 8 core is essential if you want to match per core performance.
 
anyways, I would say if an extra $100 is worth the piece of mind, go with the i7, but Linus always says build what gets you what you need now, so if you follow that, get the i5.

FireStrike/Cinebench != actual game performance. Jayz made a video and it covers this pretty well 
 

Get whatever is cheaper,if you go for the 390 dont get the gigabyte one,its hot,loud and voltage locked.Msi or Sapphire are much better

If you want "futureproof" get the R9 390. 8 gigs of vram will come in handy, since newer games will be more vram hungry, and  amd in DX12 looks more promising than the nvidia.
Also most of the games nowdays are nvidia optimized, thats why you see in some titles like witcher 3 the 2 cards trading blows. I highly doubt that if witcher 3 was amd optimized that the 970 would be as good as the 390

The 390 performs better in real-life tests (most of them, at least.) It will perform better in resolutions higher than 1080p, though at 1080p it's so little behind the 970 that it's not worth it to pay the extra $30 or so for a Maxwell GPU.
 
Also, the 390 better DX12. It runs newer games better, see the benchmarks on Battlefront (using the NVidia game-ready driver vs AMD's 15.9.1 Beta driver.) The 290X even beats the 970. I'd get the 390 any day.

Actually, most games made by EA are AMD optimized, since AMD is their hardware sponsor.
 
Battlefield (4) has Mantle, so your AMD card will run more optimized. Also, even on the NVidia optimized games, the 390 gets close or beats the 970.
 
And GTA V uses 4GB of VRAM or more @ 1080p.