Dunlop0078 :
Im not really sure, i would definitely assume the amd vishera fx cpus have the best single core performance like the fx 4300, 6300, 8320. If you really want single core performance go intel. What do you want to compare? Like a fx 6300 vs an anthlon 860k? Of an fx6300 vs an apu? It depends on the game, games that are mulithreaded dont need serious single core performance games that aren't multi threaded do. Im not really sure how to answer this question, what cpus are you looking at and what are the rest of your systm specs? i might be able to help you decide on one.
My pc specs:
CPU: AMD FX 4130 quad core processor
CPU Cooler: Standard
Operating system: Windows 8.1
Motherboard: Gigabyte GA-78LMT-USB3
Ram: Corsair XMS3 1600mhz 8GB (2x4GB)
Hardrive: 1TB S-ATAIII
Optical Drive: 22x DVD±RW DL S-ATA#
Graphics Card: Palit Geforce GTX 650 OC
Sound Card: Onboard audio 7.1
Case: Zalman Z11 Plus
PSU: Corsair CX600