Preferences? Are these what I want to have or what I buy? :)
At home all my CPU's are AMD (Phenom II X6 in the desktop, Phenom II X3 in the HTPC, E-350 in the laptop) but I'll probably buy Intel next time I buy (though so far I don't feel the need).
My GPU's in use are also all AMD (Radeon 5850 in the desktop, Radeon 5550 in the HTPC, E-350 in the laptop), but I won these two cards. I will probably own an NVIDIA chip in a Nexus 7 soon, so at least that would balance things out. :) Mmmm, just realised I also have an AMD GPU in my Wii and soon will have another one in an Xbox 360. For graphics cards (not chip) brands I don't have a particular favourite.
I do like AMD. I think it's a nicer company than Intel and NVIDIA. Plus I got a lot more free AMD cards than NVIDIA ones. Still, IMO its products are less appealing these days.
Motherboards I often buy Gigabyte because of value for money and they generally work well over time.
Other parts I don't have specific brand preferences.

