Its true though, that you have preferences.
I for instance prefer ATI to Nvidia (Though I have a Nvidia card), because they seem to perform better in 3D tasks, with menus and such where a 3d display is viewing under a 2D display.
I thought it was the one Nvidia card I had before, but this one I have now does the same thing, so the next card I get will be an ATI for that reason alone.
I don't mind too much about the CPU make, but I did have an AMD, but then switched to an Intel to get the quad core Q6600.
I also love ABIT motherboards, and haven't used any other on my own builds. They just seem more user friendly (especially in overclocking) than the likes of Asus, etc, in my experiences from building my brothers using an Asus