#4 Massimiliano Allegri
After the resignation and the departure of Antonio Conte, Juventus needed stability and they got that from Allegri.
The reaction to his appointment was bitter but it has all turned into respect over the course of five seasons.
Having stayed in charge for over 225 games already, Allegri has won 161 of them but has lost only 30.
Having won the Scudetto four times in a row, Allegri has also won the Coppa Italia four times. He's reached two Champions League finals and both ended sadly but much of Allegri's praise comes from his tactical fluidity and the intelligence he posses to dig out wins and keep his team on a steady track.
After initially playing a back-three and building on Conte's tactics, Juventus switched a back four and became less intense in their pressing but their football follows a shrewd path in trying to exploit the territorial advantage and counter when needed.
He's experimented with several formations which include a back five, a back four and a back three and he's gone on to win in each of the seasons.
Another landmark achievement for Allegri is the fact that he has worked with 62 different players during his tenure and what is important to note here is that he's a very strong builder of his team and the side has transitioned into a major threat in-spite of losing key players over the course of time.
Manchester United can certainly eye to lure Allegri and no one can fault their decision if they choose to do so because the Italian is one of the best out there.