Since taking over the reins as interim Manchester United boss in 2019, Ole Gunnar Solskjaer has surprised many and overcome doubts about his ability to strengthen the team.Manchester United have spent big on smart signingsThe signing of Jadon Sancho and the arrival of Raphael Varane means Manchester United have had one of the most impressive transfer windows across Europe.This has been a feature of Solskjaer's reign, with multiple arrivals molding the Manchester United squad into genuine title contenders. We rank the 5 best transfers made by Manchester United under Ole Gunnar Solskjaer.#5 Amad DialloAmad Diallo in action for Manchester United against FulhamStill only in his teens and yet to make a game-winning impact in a Manchester United shirt, Amad Diallo is included purely for the impact the young Ivorian could make in the future. A pacy winger capable of direct and deadly running, Diallo was bought from Atalanta for a hefty £37 million fee which mirrors the signing of Cristiano Ronaldo as a relatively unknown winger.New signing Amad Diallo is making his debut for Manchester United U23s.It only took him 14 minutes to score his first goal.Against Liverpool. 😏 pic.twitter.com/yyO6NORLw6— B/R Football (@brfootball) January 30, 2021A standout player at Bergamo, Diallo is an exciting option for Manchester United. The youngster is ready to burst onto the scene at the right opportunity and is a long-term signing that adds to United's youthful attack, which includes Greenwood and Sancho.#4 Edinson CavaniEdinson Cavani celebrates for Manchester UnitedManchester United have long been masters in the art of signing valuable experienced centre forwards. From Teddy Sheringham to Henrik Larsson's loan spell and the recent deal for Zlatan Ibrahimovic, signing a veteran striker seems to be United's speciality.Adding to the list is Uruguayan hitman Edinson Cavani, who has played for Paris Saint-Germain, Palermo and Napoli over the last decade. He is one of the most consistent goalscorers of the era and had an excellent return of 17 goals in his first season with Manchester United.What has been appreciated by fans and pundits is the intelligence and experience Cavani has brought to United's attack. An especially astute signing considering Manchester United got him at a steal on a free transfer.👍… pic.twitter.com/IFKiz9aJQk— Edi Cavani Official (@ECavaniOfficial) August 6, 2021