Ten reasons why Letterman will never be replaced

David Letterman is the last of the late-night giants. After three decades on late-night TV, Letterman will end his reign at 11:35 p.m. Wednesday on CBS.

No one on TV ever will have the impact Letterman had on the comedic landscape. He upheld the strange, the absurd, and the cynical, paying no deference to the status quo.

So we say goodbye to Letterman, the longest-running late-night host in history, with the most appropriate of numerics: 10 reasons Letterman will never be replaced.

David Letterman's tone - which ranged from bemused indifference to mild irony to enraged sarcasm - was a shock to the system when he took over his first late-night TV show in 1982. Think about it: The Lawrence Welk Show was just ending and its brand of forced innocence, faux-naïveté, and general aw-shucks-ism defined talk shows. It still does.

Letterman broke the cardinal rule: Treat your guests as though they were gods and your chat with them as a sacred ritual.

There was no reverence to be found at Letterman's desk. He didn't seem to care if he rubbed folks the wrong way. Cher was so offended she used choice epithets to describe him. Even Oprah, whose universal love embraces all beings, couldn't bring herself to like him.

As Letterman told Jon Stewart in 2010, folks who go on Oprah expect their lives will be improved by the encounter.

And they usually are.

"When these people come to this show," Letterman said, "the only thing they go home with is a bad taste in their mouth."

- Tirdad Derakhshani

Letterman had his perennial favorites: Bill Murray, Tom Hanks, Amy Sedaris, Regis Philbin. These people exerted little effort pushing product (if they even had one to push), preferring to chat with old pal Dave. But it was even more fun watching him fall in love with people.

Take last year's appearance by comedian Billy Eichner. His shtick, from his show Billy on the Street, is literally to yell at people while asking them ridiculous questions. It's funny, I promise, and influenced heavily by Letterman's own man-on-the street work. So Eichner makes Letterman play "Celebrity Child or Kentucky Derby Winner," in which Dave must guess whether a particular name - Pilot Inspektor; Little Pixie Frou-Frou - belongs to one or the other. Dave's face starts to light up. He can't stop laughing and insists on playing more. "I wish this was my show!" Letterman says. "I want to do that to people!" Because it's Letterman, you actually believe him.

- Molly Eichel

Possibly the only thing that trumped watching Letterman vibe with guests was watching him prod guests he didn't like into self-immolation. Jimmy Fallon seems to be besties with everyone who sits on his couch, but Letterman never gave disliked celebs the same courtesy. He never feigned interest or let them off the hook - both a post-Nipplegate Janet Jackson and post-prison Paris Hilton likely wished they hadn't visited. In recent years, Letterman's ire came out in his refusal to kowtow to youth culture. He looks positively bored in an infamous 2012 interview with Justin Bieber. Letterman squirms in his chair, playing with Bieber as though he's a cat toying with his prey before going for the kill. When Bieber incorrectly identifies the Sistine Chapel as the Sixteenth Chapel, Letterman can barely contain his glee.

- M.E.

Letterman has been with Regina Lasko since 1988, but that's nothing next to his longest partnership, his 33-year relationship with bandleader Paul Shaffer. The 65-year-old musician and bassist Will Lee have been with Letterman since Day One.

But is Paul an equal partner? He wasn't as much of a footstool as Ed McMahon, but he often took the brunt of the comic's moods. Nevertheless, their respect for each other is undeniable and deep.

"What this means now," Letterman said when he announced his retirement last spring, "is that Paul and I can be married."

- T.D.

Despite his daily repartee with Shaffer, Letterman has for the most part flown solo, though he has often experimented with partial sidekicks.

Chris Elliott, the greatest by far, played a host of roles. Our favorite, The Guy Under the Seats, lived under the audience bleachers and shouted threats at Dave. "I'm gonna be right here," he'd say, "making your life . . . a living hell."

Back in '82, Letterman's show featured the character Larry "Bud" Melman (Calvert DeForest). "I think it will thrill you," the short, rotund, bald man would say with a grimace. "It may shock you. It might even horrify you." Melman often went out on field trips - cameramen would capture him at the New York Port Authority bus terminal, welcoming visitors.

The most beloved figures were stage manager Biff Henderson, a perfect straight man to Letterman's goofiness, and, of course, Dave's Mom, played by Dorothy Mengering.

- T.D.

Letterman broke acts. He gave R.E.M. their U.S. television debut in 1983. He gave the White Stripes a shot in 2002 with "Fell in Love With a Girl." He fawned over Future Islands in 2014. He created musical moments that couldn't exist in any other setting. Paul McCartney played to a packed street atop the Sullivan Theater sign. Letterman donated a show to Warren Zevon so the latter could say goodbye after a diagnosis of inoperable lung cancer. "You've been the best friend my music has ever had," Zevon told Letterman.

Though Fallon can pick up some of Letterman's musical slack, one thing will never be the same: Darlene Love's "Christmas (Baby Please Come Home)." Love said she would never perform the song - which she'd been belting for Dave since his NBC days - on TV again.

- M.E.

To stay relevant, current late-night shows have subsisted on viral visibility. Fallon makes celebrities do silly things; Jimmy Kimmel plays pranks. These moments are genius in their own way but feel manufactured.

Letterman - who feared neither network brass nor publicists' ire - created moments that felt spontaneous and true. Drew Barrymore danced on his desk and flashed a shell-shocked Dave. The host pulled stunts like bum-rushing then-boss GE's offices. Then you had anything Andy Kaufman did.

Most special were Letterman's rare moments of vulnerability. Take his first show after 9/11, in which, still rattled, he starts by saying he just needs to hear himself talk and rambles from there. It was a stark moment of truth on a program cloaked in cynicism, and it was truly beautiful.   

 - M.E.

Letterman has never had much of a poker face: You could always tell when he fancied one of his guests. It was actually charming, especially when he was younger, to see the comedian stammer and stutter, pause and catch himself whenever he had a beloved as a guest.

Few megastars have flirted more delightfully with Letterman than Julia Roberts (her last appearance featured a highlight reel of their customary kisses). Another Dave fave was Teri Garr. ("I'm in love with this woman; I'd marry this woman in a second if she'd have me," Letterman once said.)

Awkward doesn't quite cover the moment in 2009 when Letterman found himself in the middle of a sex scandal just six months after his wedding to Lasko. The talk-show host admitted he'd slept with several female staff members over the years.

"I have no one to blame but myself," he told Oprah.

- T.D.

Late night doesn't matter anymore. Current late-night hosts seek to stay relevant by getting their bits shared on Facebook and Twitter the day after the show, yet late-night shows are no longer necessary viewing when the DVR or Netflix or any of myriad channels can fill that late-night void. Can you imagine Letterman even wanting to try to go viral?

There are other places to break musical acts or just generally be bizarre. That doesn't mean Letterman replacement Stephen Colbert, who starts on Late Show in the fall, won't be fun to watch, but he will never be as urgent as Letterman in his heyday. Letterman himself never became irrelevant, but his format certainly did. What matters is he's leaving of his own accord rather than being pushed out the door.

- M.E.

Would Letterman disagree with the above sentiment, that it's time for him to go? No. He's 68; he has an 11-year-old son. But, more important, here's a guy who has refused to involve the media in his farewell tour, and when he did talk, present was his trademark sneer at self-importance. He wouldn't even like this piece. As he said in a recent interview with the New York Times, "It's just a goddamn TV show."

- M.E.