All 3 are amazing -- those are the original 3 members.

Petrucci and Myung went to Berklee (Boston) together. They thought they were the only non-jazzers/classical in the whole school. One day, while having lunch, they see this guy in a Pink Floyd t-shirt............turns out to be Portnoy...........they introduce themselves and discover that he is originally from Long Island, just like they were.

The rest is history.