It was a night of serious fun filled with singing, dancing, laughter and also tears as some influential Hollywood stars gathered in New York on Monday night to celebrate the legacy of screen legend Paul Newman and his SeriousFun Children’s Network, a growing community of summer camps he created in 1988 to serve children with serious illnesses.

“This is the best show of New York City tonight,” David Letterman, who made a rare public appearance to honor his old pal, told the packed crowd at Lincoln Center’s Avery Fisher Hall.

The latenight host went on to rave about Newman’s charismatic personality. “I’m lucky enough to have known Paul Newman for quite a few years,” Letterman said before showing a montage of Newman’s frequent visits to his CBS show. “He was so generous, and he would visit us on the show and never turned us down, regardless of his schedule. His presence made everybody feel better. He was a tremendous man.”

Meryl Streep kicked off the star-studded benefit by stating that the legendary actor would have celebrated his 90th birthday last January (Newman died of cancer at his home in Westport, Connecticut, in 2008). She told the audience that the prolific star, who acted in more than 65 films, once said, “To be a good actor, you have to be a child.” Streep reasoned that it was in reference to the necessary realm of make-believe and fun — a need to experience and to create wonder.

“He used his resources to ensure that kids with serious illnesses would not be reduced to being their diagnoses,” she continued. “He wanted all kids to remain kids for as long as possible, for as long as he did. So on the occasion of his 90th birthday, we celebrate not how old Paul would have been, but how young he will stay, always, because the respect he had for the integrity of childhood captured on the faces and in the hearts of kids around the world at SeriousFun camps.”

Tom Hanks, who co-starred with Newman in 2002’s “Road to Perdition,” got emotional and fought back tears while reading a letter written by the mother of 11-year-old camper Sammi Blansett, who is battling a rare genetic disorder called Kabuki syndrome, which produces weak muscle tone and skeletal abnormalities. Hanks explained that the goal of a SeriousFun camp is to make each kid feel “empowered and capable,” and in such form, the camp has successfully empowered Blansett to believe in herself.

Danny DeVito honored Newman by admiring his good looks and thanking him for bringing the iconic character Butch Cassidy to life on the bigscreen. “His chiseled face, bright blue eyes, a full head of hair! I always wanted to be him,” DeVito told the audience. “But it’s not about what he looked like from the outside that brought us all here tonight. It’s because (of) what he offered from the inside — all the joy he gave us. And he gave us Butch Cassidy! There’s a part I would have loved to play.”

To pay homage to the Western outlaw character, DeVito donned a bowler hat similar to the one Newman wore in “Butch Cassidy and the Sundance Kid” and joined a group of camp kids to sing the film’s Oscar-winning theme song, “Raindrops Keep Fallin’ on My Head.”

George Clooney spoke passionately about Newman’s life-changing work and praised him for being a role model to all. “He is the best version of us. (And by us) I don’t mean actors or any celebrities, I mean humans,” said Clooney, who’s been residing in New York with his new wife Amal Alamuddin while filming his new drama “Money Monster.” “Paul, the world is better because of you,” Clooney said. “We owe a debt that is too great to ever be repaid, so we hope the words ‘thank you’ are enough because anything else will fall short. We thank you.”

When explaining that SeriousFun has served more than 518,000 children and families from more than 50 countries since its inception, Clooney accidentally stated that the camps have brought in sick kids from over 500 countries. “That would be too many. There aren’t that many,” he quipped, before adding, “My wife’s the smart one!” Clooney’s joke received the biggest laugh of the night.

Also a part of the evening’s nearly two-hour show was Carole King, who sang her hit “Child of Mine”; opera singer Renée Fleming, who belted out a show-stopping aria; Natalie Cole, who performed “This Will Be”; and Aloe Blacc, who enlivened the room with his chart-topping “Wake Me Up.”

(Pictured: Meryl Streep, George Clooney and Tom Hanks with SeriousFun campers at the SeriousFun Children’s Network 2015 New York Gala: An Evening of SeriousFun Celebrating the Legacy of Paul Newman at Lincoln Center’s Avery Fisher Hall)