This point is really important. For some programs, as has been mentioned already, it will be impossible to make a definitive judgment based on ranking systems. Your decision, therefore, should take into account other factors like recent hires, faculty in other departments whose work might converge with your interests in some way, the receptivity of your POIs to your work, etc. For all the noise out there about the dominance of a small cadre of elite institutions in faculty hiring, I am one who still believes fit is an incredibly important downpayment on your academic career. Go where you grow!