Red Devils manager Sir Alex Ferguson revealed recently that this was probably the best United squad "in terms of completeness" he has had under his command since taking over at Old Trafford in 1986.
"I also think that this is the most talented team, but you can only confirm this at the end of the season, seeing what the team has won.
"There is a lot of talent, I think that we are going along the right path.
"Game after game we have shown that we have a fantastic team, with a lot of talent and magnificent players, but at the end of the season we will be able to provide a definite answer if this team is the best Manchester United side of all time.
"If we win the Champions League or the Premier League we will have a better idea."
Ronaldo was speaking ahead of Wednesday's Champions League semi-final first leg against Barcelona at the Nou Camp.
United are favourites heading into the tie, but Ronaldo is taking nothing for granted against a Barca side who were European champions just two years ago.
"At this stage there are no easy games. They are all very important matches where the pressure is very high for both teams and you need the maximum concentration. Anything can happen," said Ronaldo, who is looking forward to locking horns with Barca ace Lionel Messi.
"Messi is a very good player. It is a pleasure to play with players like him. We seem similar - we always want to score and win.
"Our objective is to win as quickly as possible. We will play to find the best result in the Nou Camp. I want to win."