(CNN) -- Most of us have a favorite toy from childhood that still has the power to make us smile, whether it's a Barbie doll, a Micro Machine or the board game Operation.
What makes them memorable is the subject of a new book, "Toy Time! From Hula Hoops to He-Man to Hungry Hungry Hippos," a collection of some of the most beloved toys of the 20th century.
Author Christopher Byrne crowd-sourced the collection from readers of the popular website TimetoPlayMag.com and came up with more than 100 beloved toys. Some, like the rampaging dinosaur King Zor (1962), have faded from the cultural landscape, while others, like View-Master and Nok Hockey (which both hit the mass market in the 1940s), have been passed down through generations.
The book includes not just the most popular choices, such as Big Wheels and the Etch a Sketch, but also those that prompted the most compelling memories, serving as "a catalyst for the imagination," Byrne said. Most of our favorite toys came into our lives when we were developing our identity and figuring out the world, he said.
The toys that stick with us are those that allowed us to explore new worlds and create experiences.
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"Ultimately, play is something that happens in the imagination," said Byrne, content director of TimetoPlayMag.com. "What makes each Barbie doll unique is how a little girl creates and projects her sense of self and her fantasies onto that piece of plastic."
Other toys create strong memories simply because of their nostalgic appeal.
"Some, just by looking at them, reflect the design sensibility of the time, becoming almost works of art," he said. "We identify with them in the cultural context of their time."
So, how can you tell if a toy will be a hit for your child? When it comes to gift-giving for children, the most important rule of thumb is to know who you're shopping for, Byrne said.
"The hot toys are only hot if they're hot for your child," he said. "The toys that become memorable are the ones that connect with our interests."