Sonic Adventure
Let’s get this out of the way: yes Sonic Adventure hasn’t aged super well. Still, Sonic Adventure is an iconic Dreamcast game that served as the blueprint for many 3D Sonic games to come.
It’s a landmark game for the series as it gave voice and personality to the Sonic characters for the first time in the games. There was a burst of enthusiasm following Sonic Adventure for learning more about new Sonic “friends.” It was strong enough that it had to eventually be toned down as it grew out of hand in future games.
In any event it was a blast at the time to explore Sonic’s world properly in 3D for the first time, and reviews at the time were incredibly positive.
While the 3D Sonic genre has had its ups and downs, if nothing else, 20 years later we’re still waiting for a new Chao Adventure game.