The host of Comedy Central's "The Colbert Report" is set to head up "The Late Show" -- likely out of character. Here's a look back at Stephen Colbert's most candid moments. (Casey Capachi/The Washington Post)

When David Letterman took everyone by surprise and announced his impending retirement last week, Stephen Colbert’s name immediately floated to the top of the list of likely replacements. Not only has he had an impressive run as a late-night host on Comedy Central, but his brand of humor (quirky, sarcastic, very New York City) fits well with the iconic “Late Show,” launched by Letterman in 1993.

[Related: Stephen Colbert to replace David Letterman on ‘The Late Show’]

Still, there were many other great options that would have made perfect sense. CBS entertainment chairman Nina Tassler just gave an interview to Entertainment Weekly and explained the decision behind choosing Colbert: “He just is head and tails above everybody else and Dave is a very big seat to fill,” she said. “We’re huge fans, he’s inspired and talented for all the obvious reasons.”

So while Colbert fit everything CBS was looking for, there were many other candidates whose names were tossed out in the last week. Why wouldn’t they work? Here’s a look at what was holding each of them back.

Craig Ferguson: Though a lot of people love the bizarre antics that take place on CBS’s “The Late Late Show,” he’s an acquired taste. And that’s the problem — Ferguson is a great fit for 12:35, and simply lacks the mainstream appeal to make the transition to the more traditional late-night show at 11:35. It’s only an hour, but we’re thinking tired viewers who see him talking to his robot likely find the schtick much funnier after the clock strikes midnight.

Jon Stewart: It seems like Stewart has always been rumored to take over for these jobs (CBS talked to him years ago when going through contract negotiations with Letterman), and it’s never worked out. And honestly, he has no reason to leave Comedy Central at this point; he’s the face of the network. Plus, the network would throw endless amounts of money to get him to stay: They can handle Colbert leaving, but it would be too severe of a blow to lose Stewart.

Chelsea Handler: Yes, everyone started asking about when a woman will finally get a prominent late-night, major network gig — but her raunchy humor never seemed like an ideal fit. (Primetime CBS is a different story.) Given that she’s said to leaving E! soon, maybe Comedy Central is a better landing spot.

Ellen DeGeneres: She would have made sense as the next logical choice if Colbert had said no — but she’s got too solid a gig right now. Why walk away from the truckloads of money she gets from her wildly successful syndicated daytime talk show?

Louis CK: Hilarious comedian, yes. Interviewer? That’s a special skill set that even some late-night hosts don’t fully possess. Despite the storyline from last year’s “Louie” in which he was in line to replace Letterman, and the fact that he’s beloved by the Internet, he would have been a risky choice.

Conan O’Brien: Unfortunately, he’s got a lot working against him thanks to his ill-fated seven month run on “The Tonight Show” back in 2010. Sure, there were a lot of factors working against him at the time (“The Jay Leno Show” lead-in?) but his show failing on a major network didn’t exactly help his case. CBS likely didn’t want to take the risk and invest big money for the show to be a potential flop. Plus, Conan’s got a good thing going on TBS late night, where he can do pretty much whatever he wants.

Chris Rock: An interesting idea, but it would almost be a step down for him considering his movies still make a ton of money. Plus, his weekly HBO show ran its course pretty quickly, after 55 total episodes.

John Oliver: Oliver’s got his own HBO series on the way, and reportedly turned down an offer from CBS.

Jerry Seinfeld: Well, Seinfeld’s already hinted that it was unlikely. He likes the freedom of his own brand of Web talk show, “Comedians in Cars Getting Coffee,” where he can ask famous people anything he wants without an audience. Plus, why would someone as obscenely rich as he is want to deal with the daily grind of a talk show?

Jay Leno: Yeah. No.


Stephen Colbert to replace David Letterman on ‘The Late Show’

Letterman’s replacement: Can he (or she!) please be a grown up?

David Letterman explains why it was time for him to retire.

Some of Letterman’s best moments through the years

Letterman’s retirement signals a possible generational shift for late-night TV

Here’s what happened the moment David Letterman announced his retirement

David Letterman: 2012 Kennedy Center Honors profile

GALLERY: David Letterman’s late shows