The former head coach of the Stadio Olimpico side has hailed the former Italy international, but added that he could have achieved much more throughout his career
Totti made his official Roma debut in March 1993 and has since made over 600 appearances for the Stadio Olimpico side.
However, despite winning several individual awards, the iconic attacker never won the Ballon d'Or and Ranieri feels he could have done just that if he had the right attitude.
"Whether I think he's lazy? I have to agree with that yes. Nevertheless, he is the best player with whom I have ever worked. He could have won several Ballons d'Or had he left Roma for Barcelona or Manchester United," Ranieri said to La Gazzetta dello Sport.
"I have also worked with [Frank] Lampard and [Alessandro] Del Piero, but Francesco is the better player. The difference is that the other two have a better attitude. They always were very dedicated on the training pitch and were the last ones to leave the ground. Totti was exactly the opposite and was the first one gone."
Ranieri worked with Totti from September 2009 until February 2011, when he resigned as Roma coach after a string of disappointing results.