Oreo O's

Maker: Post
Peak Popularity: Early 2000s
Watch a classic commercial here

The urge to take your own life after finishing a sleeve of Oreos (the serving size is only three) is real. Fortunately, this cereal alleviated the creme-induced guilt by turning the cookie into a breakfast food. There was also the allure of the Creme-filling Man, the cereal's Casper-like mascot. Bring it all back to us.