What are /r/amazedme's favorite Products & Services?

From 3.5 billion Reddit comments

Name: "Optical Illusion Pixel Cards"

$10

Amazon Link:
https://www.amazon.com/Kikkerland-GG79-Pixel-Playing-Cards/dp/B00UBXVJ4C

Source Video:
https://www.instagram.com/p/BZtkuBKlWlX

This is a concept design (by Juhyun Lee for KOI & Insix Design Studio) for those who want to buy it. You can find it here (Yanko Design).

Something kinda of, but not really similar to this is this (Amazon).