Randy Rhoads would be great as a teacher, eh!? *LOL* I read an interview with Janet Robin in Modern Guitars, and Randy was her teacher!! You'll find the article here describing her experiences with him: http://www.modernguitars.com/archives/002540.html
I would choose Ted Greene, not only did he have an understanding of the guitar as an instrument, he was also well grounded in music theory and was considered to be an excellent teacher.
I think would pick Eric Clapton... just because of his evolution as a guitar player and the fact that he has style is combination of the all the great guitar players that he has studied.