#1 The Pet Rock: Invented in 1975 in California, it spread like wildfire to the rest of the country. This was a pet that required no food, no care and still gave its owner a few moments of pleasure.
#2 The Venus Flytrap: Popularized in the 1970's by "Little Shop of Horrors". Our friends at Wikipedia define it as "a carnivorous plant that catches and digests animal prey (mostly insects and arachnids). The trapping structure is formed by the terminal portion of each of the plant's leaves. The plant's name refers to Venus, the Roman goddess of love and plant life." These are so gross to watch.
#3 The Lava Lamp: Invented in the 60's, this useless but decorative lamp has a gentle flow of randomly-shaped blobs of wax suggests the flowing of hot liquid magma volcano lava. Groovy man....
#5 The Chia Pet: Originated in the early 1980's, the Chia Pet achieved widespread popularity. They became somewhat of a fad in the 1990's but surprisingly resurfaced in the late 90's and early 00's and revived it's fad status. The catch-phrase related to the Chia Pet, sung in the commercial as the plant grows, is "Ch-ch-ch-chia!" (oh go ahead, "sing out Louise", you know you want to)