What i3 chips are you talking about here? Normally I would say the i3- and 7850 as it would get a better balance of the systems above. However, there would be times where the G860 and 7870 would win out if the game is not very CPU bound and is all GPU reliant. If you can slap a 7870 on that i3 I'd go for that. If you can slap a 7870 on that i5 even better. I think I vote the middle one. The 7770 just isn't powerful enough to run much.