I would have mentioned Under A Glass Moon if so many people did not already post it. I like the solo a lot and I have to agree that it is one of the harder Petrucci solos. It is much harder to play than it sounds. His ingenuity/technique is amazing. I also believe that Kirk Hammett is really overrated. If someone unplugged his wah wah pedal he would be hard pressed to solo. As for the 5 best? ...there are way too many to narrow it down to 5.