60s - Barbie
70s - Pet Rocks
80s - Cabbage Patch Kids
90s - Tamagotchi
Created in 96, these virtual pets took the world by storm. Kids (and adults) were able to raise a digital pet. Slightly more advanced than a Pet Rock, Tamagotchis took some kind of responsibility.
00s - Baby Born
As with everything, dolls have evolved. Instead of having a Barbie doll or a Cabbage Patch Kid, the doll craze of the 00's was Baby Born. These dolls could eat and even pee themselves.
10s - iPad
Seeing kids with iPads is something that's happening more regularly, and it makes sense. Instead of just having one toy, the iPad has thousands of games available to keep kids occupied.