Use any criteria you feel is appropriate. 1. Floyd Patterson 2. Ernie Terrell 3. Sonny Liston 4. Karl Mildenberger 5. George Chuvalo 6. Zora Folley 7. Henry Cooper 8. Cleveland Williams 9. Brian London I found this to be harder than ranking the challengers from Ali's second reign. Here, Liston is obviously the best of the bunch, but that performance in Lewiston was so awful (even if Sonny was jobbed). Patterson and Terrell kind of threw me, too. In the end I ranked Patterson higher for his overall career. Williams I downgraded due to his being in less than prime condition at the end of 1966.