Easily Chris Cintron. I've always felt that John Arch, while a talented singer, was very overrated. John Hendricks had a nice voice, but I feel that, like Charlie, he would have sounded out of place on the more metal songs. Steve Stone was ok, but despite all the hype about him being the second coming of Geoff Tate, I felt he just sounded kind of... generic. Chris Cintron had a very unique and bluesy voice that I felt was strong enough to tackle the band's metal side while still possessing a sensitivity that worked well on their lighter and more emotional material. I feel his voice could potentially have served both sides of Dream Theater's musical identity well, which is something that cannot be said of the other singers they had before James, including Charlie and Chris Collins.