"I have played in some really good teams," said Giggs.
"In 1999 it was obviously the Treble side, while the 1994 team sometimes seemed unbeatable.
"But this season we have won the league for a third successive time and I think if we win the Champions League as well you will not get very many people arguing against it being rated as the best-ever United side.
"Nobody has ever defended the Champions League. To accept that challenge and succeed would, on it's own, be brilliant.
"But to have won a hat-trick of leagues as well, you have to talk in terms of this being the best team the club have had."