i can go with the 3600 and i am a very big fan of NVidia, never had anything but intel and NVidia, this is the first time i'm going for amd because of budget but gpu wise i would never go with anything other then nvidia, anyway my prob is not the change from the 3400G to the 3600, the prob is if i do get 3600 that means i need another $400+ and more for a gpu as well, which means another month or 2 of saving up money.If you're gonna build a new pc, 8x2 (16)gb 3000mhz rams would be enough for the next 5 years for sure. If you're not Nvidia fan I suggest you to get 580 Gpu since it's the one of the best price/performance gpu so far. When it comes to Cpu, Ryzen 5 3600 would be cool but since I have no clue about your budget, I can assure say that even ryzen 5 2600/x is good enough for gaming.