The No. 1 reason fans are turning out: They love David Letterman

In his final weeks as host of CBS’ “Late Show,” David Letterman has recruited a cavalcade of bold-face names, including President Obama, Tom Hanks, Julia Roberts, Tina Fey, Oprah Winfrey and even, rumor has it, former archrival Jay Leno.

But for the dozens of fans who queued up on a recent afternoon outside the Ed Sullivan Theater, home of CBS’ “Late Show” since 1993, the real draw isn’t the A-list guests but the gap-toothed host whose 33-year career in late-night television ends May 20.

A comedian whose sarcasm and subversive wit seemed revolutionary back when the gracious Johnny Carson was late-night’s undisputed king, Letterman, 68, ranks as the format’s elder statesman. Cited as an influence by younger hosts Conan O’Brien and Jimmy Kimmel, Letterman trailed Leno in the ratings for most of his run at 11:30 but has inspired what appears to be a greater level of devotion from fans.

“I’m, like, freaking out. This is a dream come true,” said Donna Zurzola, from Ridgefield, Conn.

A Letterman acolyte since his days on NBC’s “Late Night” in the early ‘80s, she stood patiently in a line that snaked down Broadway, past a vendor selling hot nuts and around the corner onto 53rd Street. This was to be her first — and last — experience as a “Late Show” audience member. “I waited 30 years for this,” she said, proudly brandishing her ticket for a CBS page.

Another superfan, Lois McKenzie, 52, had traveled to New York from her home in Lexington, Ky., with the sole purpose of attending a “Late Show” taping before Letterman’s retirement.

“I’ve been to New York a lot and always said I’d get to the show, and then all of a sudden it’s coming to an end. We got real lucky. We signed up about three weeks ago. Got the airline ticket, got the hotel room,” she explained as she and her husband, Alan McKenzie, stocked up on “Late Show” merchandise inside the Hello Deli, the modest convenience store on 53rd Street made famous in one of Letterman’s recurring bits.

“We got married five years ago, and he’s learned to sleep with David Letterman,” she added, as owner Rupert Jee rang up their order — throwing in a “Late Show” mug on the house.

The show has been a life-changer for Jee, who took over the then-failing deli a few years before “Late Show” arrived at the Ed Sullivan Theater. He is one of the last original tenants to survive in an increasingly pricey neighborhood, thanks in part to the patronage of Letterman fans.

In addition to “Late Show” merchandise and themed sandwiches (the top-seller is the Shaffer, a chicken cutlet and American cheese combo named for bandleader Paul Shaffer), Jee also sells shot glasses and T-shirts featuring his own image ($12). His bodega has become an unofficial commissary for hungry “Late Show” crew members and the paparazzi who lurk outside the theater’s stage door.

“From a selfish standpoint, I wish he’d stay a few more years,” added Jee, who was caught by surprise when Letterman announced his retirement in April 2014. “It threw me real off. I was pretty depressed about it.”

Some longtime viewers recalled just how radically different Letterman seemed when he arrived on television in the early ‘80s — beginning with, of all things, a short-lived morning program on NBC, before launching “Late Night” in 1982.

“Carson was old school, and Letterman was fresh — he was more the collegiate kind of vibe,” Paul Wedel, 58, who was able to score standby tickets while in town from Berkeley visiting his daughter. “We were all smoking dope, and it was all good.”

Others weren’t even alive when Letterman’s “Late Show” debuted in 1993 on CBS, the network that welcomed Letterman after Leno was named Carson’s successor on “The Tonight Show,” setting off one of the most intense rivalries in late-night television.

“He’s just such a renowned person, he made such a mark in this business,” said Emily Garren, an 18-year-old broadcasting student at Manhattan College. She and a classmate, Jordan Bautsch, also 18, were wandering the neighborhood in search of a Chipotle last week and put their names into a “Late Show” lottery on a whim. They got a call that they had won tickets just two days ago.

“I was, like, jumping up and down,” said Bautsch.

For others, it wasn’t so easy. Jake Barcelona, 18, a student from Chicago, applied for tickets through the “Late Show” website in early April and then had to prove that he knew who “Late Show” announcer Alan Kalter was in a phone call from an audience coordinator.

“[Letterman] keeps it youthful, even though he was born in the ‘40s,” Barcelona said, standing at the front of the ticket-holder line with a group of friends that included Neil Harris, a student from Letterman’s alma mater, Ball State University, in Muncie, Ind.

“I like how Dave’s laid-back, he doesn’t really care,” said Harris, 18. “He has a nice energy.”

While a highly informal survey of “Late Show” ticket holders suggested that most are excited about late-night’s new generation — “Tonight Show” host Jimmy Fallon seemed to be the overwhelming favorite — others plan to give up the habit once their beloved Dave takes his final bow.

“I’m just going to miss him,” said Diane Murphy, 60, of Queens, clad in a “Late Show” T-shirt. “I feel like he’s a family member.”