Hello, I built this computer 3 years ago and I feel like upgrading it to have better graphics, I could spend around $500-600.
I would like to see which are the best options and what components I could still keep or add.
PCPartPicker part list / Price breakdown by merchant
The old Haswell chips are still running strong for 60hz gaming so personally this is what I would go with.
Add an SSD for your boot drive and commonly used software, upgrade the graphics, and get a new power supply.
Upgrade your CPU to an overclockable chip, like the 4690k or any other CPU that has a K at the end, then buy a GPU like the 1060 GB or the 1070.