Amazon is the best shopping portal and the good thing is you will all almost all the products there with many Brands.
As compare to flipkart and paytm or any other shopping portal, Amazon provides good discounts and quality of the products. The refund policy of Amazon is very good and unlike other compaies Amazon belives in customer satisfaction.
I really enjoyed while shopping on Amazon but some times you might face issue while paying online as faced it last week. The problem was I was not getting OTP from the Bank doing online payment however you can pay via netbanking as well.
Overall Amazon is a good shopping portal and you can trust on it.