I like Intel CPU's over AMD CPU's. My preference used to be based on everyone testing everything more thoroughly on Intel CPU's that AMD, and thus fewer weird issues with drivers, software, etc. on Intel. These days, Intel CPU's might perform better per $ cost as well, although I'm not positive about that.
I prefer nVidia GPU's to AMD GPU's. My preference is based on, long ago not liking the quality of Radeon drivers vs. GeForce drivers and liking the antialiasing of nVidia cards better than Radeon cards. These days, my preference is that nVidia seems to use less wattage than AMD GPU's for similar performance. Also, I have been happy with nVidia cards in recent years.
I get i5 CPU's because they are faster (usually -- can depend on some specifics) than i3's but significantly (to my measure of significance) less costly than i7's. So, for me, it is a happy medium.
I have found that even an i5-2400 (a Dell computer, which cost $500 when new) and a GeForce GTX 750 Ti card (which costs about $130 today) gives me approx. 60 fps in AH3 beta flying offline around a base with drones.