Super Mario 64 is a phenomenal game that means a lot to me, it really perfected platforming in 3D space. It was the first home console game and first 3D game I ever played. However, no game captures the magic of video games the way the gameplay of NiGHTS into Dreams does. The level design and music was amazing, the sense of speed and fluid controls was unmatched. Even the boss fights were unique and incredible. It gets my vote.
Another masterful Saturn release was of course Panzer Dragoon Zwei, which was a massive step over the original, and along with NiGHTS, perhaps the most aesthetically pleasing 3D games of the era, and it really expanded on the lore of the universe.
The first Crash was solid, but I just cannot fathom how they came up with the save game mechanic. It is one of the most stupid game design decisions I have ever seen.
