Im not really big on brand loyalty but for some reason ive always liked Sega, i guess it was because when you were younger you had to either like sega or nintendo and i had a megadrive and then a dreamcast so feel kinda loyal to them.
I guess Amazon aswell. I just think its the most useful website for buying everything really and so easy to use. The one click ordering is the best thing on the internet. Also Google, but everyone likes google.