spoiler Alert! I think it's Patrick Jane for several reasons...
1. Red John has "disciples" and Jane can hypnotize and command people to do things very easily;
2. Red John knows whatever Jane is thinking and even knows his childhood memories that he never shared with anyone;
3. Jane could have developed a split personality due to issues in his past and his difficult childhood;
4. Either Jane unfortunately killed his own wife and daughter without realizing it due to a split personality OR he became just like the person that killed his wife and daughter from trying so hard to figure out who had done it, and the real killer got away (I'm still working on this one);
5. Jane knows more about Red John than anyone else;
6. If its anyone else on the list of 7 people, it just wouldn't be very interesting or enough of a twist;
7. Jane would never name himself as a suspect on his own list because he would never know he had a split personality.
