Olympics chief Jacques Rogge heaped praise on Greek organisers and declared the Athens Games an all-round success.
Rogge also warned there could be more positive drugs test to come
Television ratings are 15% up from the 2000 Games in Sydney, while ticket sales have topped figures from the Seoul and Barcelona Olympics.
"The organisation was outstanding and we had competitions in state-of-the-art venues," said Rogge, who described the security precautions as "flawless".
"They really did a fantastic job. I am very, very happy about the Games.
"We have discovered a new Greece. Greece was great for the Games.
"These have been unforgettable dream Games. These Games were held in peace and brotherhood. These were the Games where it became increasingly difficult to cheat and where clean athletes were better protected."
Rogge's predecessor Juan Antonio Samaranch had hailed the 2000 Games in Sydney as the greatest Olympiad ever.
But Rogge gave a diplomatic response when asked whether the Athens Games were better.
He said: "You cannot compare Games that are held at different times and in different countries."
But despite all the praise, Rogge sent a chilling warning there could be more positive drug tests than the 22 recorded so far in Athens.
"The list is probably not over," said the Belgian. "You have 10,500 athletes in the Olympic village, you do not have 10,500 saints. You will always have cheats."
The combined performances of China, Japan and South Korea also impressed Rogge, who described their efforts as the "awakening of Asia" and an ominous sign for the rest of the world ahead of the 2008 Games in Beijing.