My current CPU is the i3-3220 but I was thinking of upgrading to the i7-3770 because it is within my budget for a CPU upgrade.
The CPU cooler came with the i3-3220 CPU and I was going to just swap the CPU at this stage.
My motherboard is Gigabyte z77x-D3H with an LGA1155 socket and it would support the i7-3770
I have 16GB RAM
I have 1 SSD of 1TB and a secondary HHD of 500GB
My GPU is he GeForce GTX 960 with 2GB VRAM
My PSU is 100W
My chassis is full tower with 5 fans not counting the cooler fan
OS is Windows 10
Monitor 27" PLL2410W
BIOS F16
I think the i7-3770 would be a terrific upgrade, especially for the money. It would open up doors the i3-3220 may never venture toward and combined with the GTX 960 which still has some punch left, the overall difference should be tremendous and the machine would be able to drift into mid-stream and provide a good kick for the buck in games. The Core i7-3770 would support well any GPU that is within x2 times faster than the GTX 960 so a moderate GPU upgrade may not be out of the list until the time comes for an entirely new system.
There are two things to think about at this point.
1. Windows 10 support ends next year. However, I think software and games will continue to support it for quite a bit more.
2. Your PSU Wattage should be high enough to support any potential future graphics card upgrades.
PS. Have had a Core i7-3770K (managed to overclock it up to 5 GHz w/ Corsair H110 water cooling) back in the day alongside 2x Sapphire Radeon HD 7870 GHz in CrossFire and the chip was pure gold.