I don't think anyone is ever going to suggest that Amir Khan is, or was, an all-time great. He did have a very good world class career, exciting fights with never a dull moment, earned tens of millions, became a household name, international popularity, world class wins on the biggest stages in boxing. He did well.
I wonder by the way... was Khan ever the #1 in any of the divisions he fought in? Does anyone here know?
No, I don't think he ever was even after beating Malignaggi and Maidana in 2010, The Ring had him at number 2 behind Bradley on their end of year ratings.