I can only limit to 3?
For the record, I really like John's slower stuff just as much as the fast and furious parts.
Really hard to choose, but if forced to...
Fatal Tragedy
The Test That Stumped Them All
Nightmare to Remember (esp that riff at 9:31)
My first meet and greet with them, I asked John what scale he used for that 2nd solo on Nightmare. His eyes got real big, he paused and said "You know, I have no idea...I'd have to look it up!"
Love that guy