Headphones.com - headphones, tax-free
Drop.com - general hobbyist goods
DigiKey/Mouser - miscellaneous parts
Your local bougie salon - high-quality body products (bodywash, hairspray, etc)
Bed Bath and Beyond - bedding and bath products
Design within Reach - furniture
Ubiquiti - wireless APs, PoE switches, and the nicest Ethernet cables I've ever used
ProtectLi - firewalls
Crowdsupply - miscellaneous gadgets for supernerds
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Best way to find a good quality product is to go to the hobbyist subreddit/community for said product and see what vendor people use. Also, r/BuyItForLife.