If you were to walk into my house you would see a lot of devices made by (or at least branded by) the same hand full of companies. My philosophy has always been, I'll continue to buy from a company until they give me a reason not to.
HP – Desktops, Laptops, Printers, Monitors, Keyboards, Mice, Flash Drives
(Desktops and Laptops are Intel CPUs, Nvidia GPUs, WD or Intel SSDs only)
Sony – TVs, A/V Receivers, CD/DVD/BD Players, Cameras, Camcorders, Voice Recorders, Speakers
APC – UPS Battery Backups, Surge Protector Power Strips, Multiple Outlet Adaptors, A/V Power Center
Cisco – Wired Routers, Wireless Access Points, Managed Switches
StarTech – Every HDMI Cable, Display Port Cable, CAT6A Ethernet Cable, USB Cable, Hard Drive Dock and various adaptor
Western Digital – SATA and NVMe SSDs, 2 and 4 Bay NAS', USB HDDs and SSDs, SanDisk Extreme Pro SD and Micro SD Cards
Pelican – Cases, Duffel Bags, Tactical Flashlights
Vehicles – Ford only. Been a Ford family since the '40s, no plans to break that tradition.
Clothes – Rebook mostly. Because I'm extremely fat, and their sizes tend to run big.
Batteries – Duracell usually. We provide Procell AA, D cell and 2032s with the equipment we build at work, and can get them at or near cost for personal use through the company account.
Shipping – UPS typically. Despite having friends and family that work for FedEx, too many bad experiences.
Although It's limited to just two desks and one office chair at the moment, Serta and Bush Furniture. Both are somewhat local companies to me, with each having factories a mile apart from each other in Jamestown, NY. My two desks are from Bush, my office chair is Serta. When I get a new mattress and box spring set next year it will be Serta
Companies not allowed in my house: Apple, AMD, Mars, Inc/The Wrigley Company, anything associated with Elon Musk