Superman has returned to Britain after almost 20 years, with stars Kevin Spacey, Kate Bosworth and Brandon Routh attending his latest UK premiere.
Bosworth said her co-star was "going to go a long way"
Superman Returns director Bryan Singer said there were more fans in London's Leicester Square than had been at his X-Men premieres - and "more screaming".
Routh said that playing the iconic superhero had been a "great honour".
The film, in which Superman returns to Earth after five years away, has been a critical and commercial hit in the US.
Superman last appeared on cinema screens in the 1970s and 80s films starring Christopher Reeve, and has featured in other movies and television series since his comic book debut in 1938.
Singer, who has been linked to a possible 2009 sequel to the new film, said he was merely the current "custodian" of the character.
"Superman means something to everybody - he's been around for 70 years. I wanted to get as much of it right as possible," he said.
The director, who shot to fame with 1995's The Usual Suspects, said Thursday's premiere was bigger than those for his two X-Men films.
"This is pretty incredible: more people, more intensity, more excitement - more screaming."
Routh added: "It's a fantastic turn-out. Everybody seems excited.
"It didn't rain, which is good, although I guess Superman could do something about that if it did."
The 26-year-old, who was an unknown actor when he won the part, said: "It was just a real great honour for me."
Bosworth, who plays reporter Lois Lane, said that she had done many of her own stunts in sequences including one on board a plane plummeting to earth and another on a sinking ship.
Singer says being adopted gives him an affinity with Superman
"The airplane sequence and the water sequence at the end, they were two of the most difficult action sequences in the film - there were lots of scrapes and bruises," she said.
But Singer said there was more romance in the film than in any of his previous movies, with producer Gilbert Adler adding: "I think people may shed a tear or two."
After Superman's five-year absence from Earth, he returns to find the love of his life, Lois Lane, engaged to another man.
"There is only so much he can do, because he is still the good guy - Lois has to figure it out for herself," said Routh.
The Man of Steel also has to once again face his nemesis, criminal mastermind Lex Luthor, who is just out of prison but still bent on world domination.
The part is played by Spacey, reunited with the film-maker who directed him to a best supporting actor Oscar in The Usual Suspects.
The actor said: "Lex Luthor is such an iconic part - you can have a lot of fun with it."
Spacey and Singer had for years wanted to work together again
It also means that, like all the film's main characters, there is now an action figure of him.
"It looks sort of like me - bald and crumpled," Spacey said.
He added that he would be interested in reprising the role in a follow-up film if it was again made by Singer.
The director himself simply said: "Right now I need a vacation - it's been a long two years."