Journey to the Center of the Earth is a killer ride. Very magical, and far better than Test Track (but then GM would not have sponsored Journey!).
The size of the final AA figure of the Lava Monster is HUGE HUGE HUGE and, man, does the car take off after that! There are also some good dips, which Test Track lacks.
It's funny: I was standing in the center of Mount Prometheus in Mysterious Island, dead center of the volcano, and I heard this whizzing around me. At that moment I realized that the vehicles from Journey speed around in a circle exactly the same way that the Test Track vehicles do at the end of the ride, but here it occurs inside the volcano.