Giggs, who lifted his 11th Premier League title on Saturday, admitted he struggled to select his best ever team - and even resorted to picking two goalkeepers: Peter Schmeichel and Edwin van der Sar.
"Peter was one of the best players I played with," he said. "He was a matchwinner who would save the game for United because he was such a good goalkeeper.
"Now I play with Edwin...they are both great goalkeepers. It wouldn't matter who played in goal."
The Welshman's midfield of Beckham, Paul Scholes and Roy Keane - plus himself, of course - was key to the Treble-winning side of 1999.
Giggs reserved special praise for Scholes, saying: "He does things I couldn't do. The time he has on the ball, his range of passing and ability to score goals make him probably the best I've ever seen."
The forward pairing of Eric Cantona and Wayne Rooney completes his all-conquering side.
"They are players who have come through the system...players from different countries and background that sums up Manchester United," he added.
Giggs's XI: Schmeichel/Van der Sar, Neville, Stam, Ferdinand, Irwin, Beckham, Scholes, Keane, Giggs, Cantona, Rooney.