I just bought a bunch of clothes off Amazon for the first time! It was about as hit-and-miss as other online ordering experiences from ASOS and Modcloth (which are the other two stores I buy from most often.)
Best of the bunch was this dress by Ella Moon (which i think is an Amazon brand?). I got it after I saw it on a Youtuber I really like, and I was really impressed by the quality and weight of the fabric. I also kept this blouse (also very well-made), this blouse (less well-made but decent for a work blouse), and this blouse, which I really liked the feeling of. I tried this skirt, which was recommended by someone in one of the other FFA Amazon threads, but it didn't really fit my proportions and the fabric felt a little cheap. Overall I really like the slightly boho Ella Moon brand. I really wanted to like this blouse, but I was absolutely swimming in the smallest size available.
Oh, and I ordered one of these "pawtriotic" tops for 4th of July, and it was definitely a keeper.