"If I was asked to pick who was the better of the four of us, and I am on record as saying Imran because he was a versatile batsman, potent strike bowler and charismatic captain," he said.
"As a batsman, he could bat anywhere in the top six, sometimes in the top four, and play any type of innings depending on the circumstance of the game.
"As a bowler, he was a potent strike bowler ... His record suggests he was a fine bowler. He was also a charismatic person, a good and successful captain for Pakistan. He had a lot of respect, he had the package," Hadlee added.
However, Hadlee had a special place for former West Indian captain Sir Gary Sobers as an all-rounder.
"Sobers traditionally has always been regarded as the number one because people would pay to go and see him play. Very flamboyant, rhythmical batsman and bowler, fielder, captain. The whole package and the stats would back that up," he said.
Hadlee, nevertheless, regarded himself as the better bowler of the quartet, but admitted his weaknesses as a batsman.
"I scored less Test hundreds than anyone else, my batting average was lower than the others. So while I had some good innings, my batting was inconsistent. I wouldn't put myself in that same category, actually, but as a bowler definitely," he said.
Talking about the rivalry between the four, Hadlee said the 1980s was a fascinating era with the four all-rounders competing for a space of excellence.
"I didn't want to get out to Kapil or Immy or Beefy but I certainly wanted to get them out when I bowled. So that competition actually grew and that motivation actually grew," Hadlee said.
Hadlee rued that the era of great all-rounder was fast coming to an end and South Africa's Jacques Kallis is one of the few, who has adapted to all formats of the game and survived.
"Statistically, he (Kallis) is the greatest all-rounder ever in the history of the game, no question about that. But obviously as time has moved on in his case, he is now being more selective. But I still would probably think his focus is Test cricket," he said.
On the ball-tampering controversy, Hadlee said though reverse swing is a fascinating craft, players should not indulge in unfair practices to get the ball to do something.
"You can use natural saliva, sweat on the ball, it is having a good effect on the game. But you can't use fingernails or anything of that nature. If you are throwing the ball on a rough surface that scruffs the ball. What's wrong with that? You are using the facility allowed to you," he said.
Hadlee admitted that he encountered reverse swing when he was playing but did not know what it was.
"Sarfraz Nawaz (Pakistani pacer) was doing something with the ball. But later we came to know Pakistan had developed or found out what reverse swing is by looking after the ball," he said.
Hadlee praised the current fast bowlers including England's James Anderson for learning reverse swing to doing it very effectively.