My aging system is as follows
4790k (not oc yet)
8gb ddr3 Kingston ram
1060 6gb
At the moment I am gaming on a 60hz screen and don't have much trouble staying around 60 fps in any game I play. However in the coming months I would really like to upgrade to a 144hz 1080p screen and 1070 (maybe ti) if my system can still squeeze itself for a couple more years and hit 144 fps or as close as possible over 100. If not it's going to be a whole new system upgrade. CPU, mobo, ram and possibly PSU.
I don't have the money to do both upgrades at once. I'm more learning towards the system upgrade than monitor and gpu but I have never played on anything higher than 60hz really want to see how nice it is.