Benitez has discussed the games which have shaped him in an interview with Guillem Balague for the BBC's Football Daily podcast.
And the 59-year-old – who is out of contract at St James's Park this summer – has chosen one Newcastle fixture.
Benitez joined the club in March 2016 following the dismissal of Steve McClaren.
The club was battling to stay in the Premier League at the time, and Benitez couldn't stop the inevitable.
United were relegated before the end of the season, but the club's fans made an impassioned plea for him to stay on the final day of the campaign.
Benitez has chosen the final game of that season – the stunning 5-1 win over Tottenham Hotspur at St James's Park – as one of his most memorable games as a manager.
United's supporters convinced Benitez to stay that afternoon – he signed a three-year deal after talks with owner Mike Ashley – and he guided the club out of the Championship at the first attempt.
"The problem we had when we arrived was we just didn't have time," said Benitez.
"We thought 'massive club, massive stadium, fans behind the team'. Everything was right, but we had 13 injuries when we first arrived.
"That (the fans) was another thing that made you think 'this is a massive club, and you can do something with these fans behind you'.
"That was a key factor in my decision (to stay). I was talking with Mike Ashley after the game, and he was asking me 'what do you want?' We were talking about what we thought was needed to win promotion back to the Premier League.
"We didn't realise how difficult it would be in the Championship.
"But our team was solid, we were strong in defence and we were fine in attack. That's the key – if you want to win trophies, you have to find the balance."
Benitez is "waiting for answers" from Ashley and the club's hierarchy after outlining what it would take to persuade him to stay at St James's Park.
"We finished 10th in the Premier League last season, and now we're talking and waiting to see what we can do in the future," said Benitez.