I’ll start - I don’t shop a lot, but if I had to buy stuff like hardware parts, I do use Amazon sometimes, but if I can, then I try to use Flipkart. Realizing how it has turned into a monopoly, I try to look for alternative websites, and check if they’re trustworthy.
If I remember correctly, the last three items I’ve bought online were hardware parts from some local websites. The chi-fi IEMs were bought through headphonezone.in, and they were super-fast in delivery - I had to wait for only four days.
For people in Germany or Austria, Geizhals is great. It shows you the cheapest seller for every product and has a ton of information for each product that you can filter by.
Also, there is this (German) collection of online shops sorted by categories.