masterflarg :
EpIckFa1LJoN :
That largely depends on what resolution you intend to run.
There are two schools. High-res and high refresh rate.
If you play competitive eSports or FPS games, you would be better off going with a high refresh rate monitor. That seems to be the consensus on what is the "best" for those type games. I for one have an incredibly difficult time telling 144 from 100. However, 60-100 or 144 is incredibly noticeable, especially if you are used to higher refresh rates. If you are gaming at 60Hz 4k you will need a 1080 Ti to hit Ultra on a lot of games, even 3-4 year old games. If you are playing at 2k or 1080p any number of GPU's will work. Then there is UW 21:9. In short I need to know what monitor you want/have to make a good GPU suggestion, I can also suggest good monitors based on your budget.
Another thing to consider is G-sync vs. Freesync if you have, or want, a monitor with either of those you will be limited to Nvidia or AMD tech respectively.
As far as the CPU, that entirely depends on your budget and what you play. For the most part a Ryzen 1600 will do you just fine, but there are several games where something like a 6700k/7700k will absolutely smoke it in performance. So what games do you play most?
You're going to want to upgrade most of your rig it sounds like, and even depending on what card you want you may even need to upgrade the PSU (at the very least it would be a good idea to do so if you end up getting a 1080 Ti or something).
So coming up with a budget range is a great start.
As far as budget goes. I'm hoping to spend like 400 - 500 at most right now. So if that means just upgrading one piece and coming back that's fine. I'm just not sure what direction to go in. If I should upgrade the Motherboard too or what not.
If that's the case I have a suggestion. I would upgrade the GPU first and come back and upgrade the CPU/mobo later, but I would definitely upgrade those. With the way prices are right now A GTX 1070 would be a good upgrade for you. It might be quite a bit more GPU than you need right now and it will quite possibly bottleneck with your GPU, but for 400-500 (hopefully you mean USD) a total system upgrade isn't going to be much of an upgrade.
If you aren't talking in US$, I would go down to a Radeon RX 580 or a GTX 1060 6GB (about the same price about the same performance).
But for that range in US$ the 1070 is your best bet (if Vega 56 prices come down that's not a bad option either.)
With either of those you can either go 1080p 144Hz, 2560x1080 60-100Hz (UW resolutions are freaking AMAZING for MMO/RPGs), or 1440p 60Hz. The 1070 and Vega 56 will handle all of those resolutions well, I wouldn't go higher than that though (3440x1440, 1440p 144Hz, 4k, etc.) you might not have problems in some titles but others you will find yourself cranking down settings to unenjoyable levels (and no one wants to do that) If you literally just want 1080p 60Hz I wouldn't get anything more than a 1060 6gb or an RX 580, but be warned none of those will handle 4k well in gaming situations (1070/ Vega Included)
As for the CPU upgrade. I would wait and come back and get an 8th gen CPU (or later gen when they come out, specs will be different, or a Ryzen CPU. For your budget (400-500) I would suggest either a Ryzen 1600 or an i3 8350k. Both should perform similarly, but the Ryzen will have 6-cores vs the i3's 4, but the clock speeds will be substantially higher on the Intel, making the tradeoff of cores almost negligible. (disclaimer: I have yet to see any benchmarks comparing the two, almost all are focused on the i5 and i7 8th gen). The Intel will be slightly more expensive due to the price of Z370 boards (which you will need in order to utilize the OC capability of the k-series chip). But either one will do fairly well in pretty much any gaming situation, with the i3 being slightly better rounded for unoptimized games.
From what you described as what you play I would go with the i3 since it has higher clock speeds, and older games tend to not use more than 4 cores well.