TBH i hate comparing coaches, cause they came in to do different jobs; it is like comparing a coach that can bring a traditional strong team e.g. Italy, France to win the WC better or a coaach that is able to bring an extremely underdog team, e.g. China, Canada, Monaco, Korea to qualify for way more they are expected like semi finals, round of 16 etc.
Cause Lippi did the former, but not the later.
Mainstream will glorify the former though.
I am not too fond of Conte cause his background, and his fanboys that tries to belittle Simone to lift Conte, but I still appreciate his work here and Spalletti's.
My personal favorite is Simone though, even way before this season, but it has to do with his coaching style and tactical style, also his personality.
Like I really like the story back then when he was still a player, his brother said he didn't take the summer off to train harder and improve himself, that was around when Lazio pretty much losing all their stars.
That is the kinda guy you would like him to stick around.