I know this is rather wide topic to discuss so I would like to narrow it somewhat down. Mainly things that are bought somewhat regularly but, not a weekly basis.
Phones. Do you stick with iPhone and prefer them over android based like Samsung or Sony? Cars. Stick with one brand when you consider switching vehicle? Computer parts. AMD or Intel? AMD or Nvidia? Playstation, Xbox, or Nintendo? Suggestions that I had on top of my head.
Phones... I like to switch. Atm using Samsung Galaxy S8. Before that it was iPhone, before that it was Android. First smartphone was an Android one, however I do have first gen iPod Touch so I knew how they operated. Regarding older phones I was somewhat brand loyal as I had mostly Nokia phones, except for one Sony Ericsson. My next phone will most likely be iPhone unless they are to expensive.
I don't really have had enough experience or owned cars to say anything. Other than avoiding Citroen I don't have much of a preference.
GPU wise I am definitely leaning towards Nvidia. Though if you wanted the best I don't think AMD has been an option since their 7970 or R9 290 cards. Latest release from them is looking good though.