!!In general:
* ToughActToFollow: Every new version of ''The Tonight Show'' is inevitably compared to the one that preceded it; for example, Jay Leno's version was compared to Johnny Carson's version. Conan O'Brien's version was compared to Leno's ''first'' version, etc. Occasionally the hosts will call attention to this; after one music act, Leno quipped, "This is not your father's ''Tonight Show''."

!!''Tonight! America After Dark'' (1957) provides examples of:
* TheyChangedItNowItSucks: It was barely even anywhere near close to being the same show.

!!Johnny Carson's incarnation (1962-1992) provides examples of:
* HilariousInHindsight: In Letterman's time as a guest shortly after it was announced that Leno was succeeding Carson, Johnny asked if Dave could imagine doing the job for another 20 years. Dave broke out into laughter at the thought. In the end, Dave '''would''' go on to host for '''over''' 20 years more, before his eventual retirement in 2015. He ended up hosting ''Late Night'' and ''The Late Show'' for a total of 33 years, just a few more than Johnny himself.
* TearJerker: Carson's final regular show featured Robin Williams and Bette Midler. The latter ended up inspiring two heartbreaking moments:
** During the interview portion, Carson remarked that "Here's That Rainy Day" was one of his favorite songs. Midler immediately began singing it, and even got Carson to join in. The lyrics--"Where is that worn-out wish that I threw away / After it brought my love so near?"--are particularly poignant, and hearing Carson perform it is beautiful and sad.
** The final moments of the show saw Midler personally serenading Carson with "One For My Baby," another torch song about the end of a long love affair (the perfect tribute to Carson's time on the airwaves); the emotion in her voice is palpable as she sings it. Two moments in particular stand out. At one point, a cameraman noticed that Carson himself was tearing up, and used an angle that had never been done on the show before to capture him looking at Midler as she sang. The second is even more powerful: after Midler finished the song, she was handed a large red lei (a reference to her birthplace being Hawaii), dashed over to Carson, put it around his neck, hugged him...and then absolutely ''burst'' into tears. She was so overcome that she ran off the stage to cry, barely able to keep from breaking down right then and there.

!!Both (1992-2009, 2010-2014) of Jay Leno's incarnations provide examples of:
* CreatorsPet: He makes the network a good amount of money for not much cost or risk, and they've been afraid of the possibility of him competing against their programming on another network.
* CriticalBacklash: Against Leno.
* FunnyAneurysmMoment: During the last week of Leno's first run as host, he had Conan O'Brien on as a guest. During the interview, Leno repeatedly stressed that NBC did a great thing by keeping Conan on through a couple of very poorly-rated years and letting him find his footing and eventually become successful. As it turned out, NBC wasn't interested in giving Conan a second opportunity to play around to find what works.
* InternetBackdraft: Debates on whether Leno is funny or not can get heated, especially after the conflict with Conan. There was debate about his conduct during that which led to some backdraft for him, but the backdraft towards NBC was pretty much unanimous.
* MisBlamed: The initial reaction to Conan's departure from ''Tonight'' had some of this for Leno, namely on how plenty of people online (and even a bit on TV) thought Jay forced NBC to give him back ''Tonight'' just to spite poor Conan. However, the decision mostly rests with NBC executives, and Jay really can only be blamed for accepting the job back instead of leaving.
* NeverLiveItDown: Double subverted. Despite what some Creator/DavidLetterman fans think, Leno ''did'' live down the "talk show wars of '93" ... and that situation for Jay vs. Letterman became a popular topic once again (in which even ''Tonight'' itself gave it some LampshadeHanging).
* RonTheDeathEater: Leno got this treatment by some Conan supporters.
* TearJerker: [[http://www.youtube.com/watch?v=BM9T1oO_umM Leno's farewell speech on his final show, February 6, 2014.]] No matter how you feel about the man himself, you can't help but end up choking back tears, especially when he talks about [[TheWoobie losing (more or less) his entire biological family after first starting on the show]] and how the staff eventually became his family.

!!Creator/ConanOBrien[='=]s incarnation (2009-10) provides examples of:
* BrokenBase: Conan vs. Jay, which has parallels in the original Jay vs. Dave BrokenBase.
* EarWorm: "Puppies dressed as cats! Puppies dressed as cats! Sometimes life will let you down and make you say "Oh drats!", but all of you are gonna love our puppies dressed as cats! Puppies dressed as cats! Puppies dressed as cats! Puppies dressed as cats! Puppies dressed as caaaaats!"
* FunnyAneurysmMoment: In a sketch where Conan made a big sign for the exterior of the studio, he joked, "They're gonna kick us off this Universal lot ''so'' fast." Oh he had no idea...
* HarsherInHindsight: Conan's first guest during his tenure on the show was Will Ferrell, who sang a ''farewell song'' to welcome Conan onto the show. When Conan called him out on it, Ferrell replied that networks are fickle, and one never knows when the show might be cancelled. Everyone took it as a good-natured gag, thinking that booting Conan off the show would not happen - at least, not as soon as it did. Ferrell was also Conan's last guest, and dressed as a hippie, played the guitar and sang a real farewell song, accompanied onstage by his wife who was pregnant and close to giving birth at the time.
** Conan might have jinxed himself during a final interview on the Today Show prior to moving to Los Angeles to host the Tonight Show. Matt Lauer asks Conan if he would consider coming back to New York for a visit after a year (of hosting the show). Conan jokingly replied that he wouldn't be on television in a year.
* HeartwarmingMoments: David Letterman, one of Conan's comedy idols and his predecessor on ''Late Night'', going absolutely nuclear on NBC and Jay Leno. Letterman has his own reasons for disliking Jay Leno, but it's gotta be nice to know that your comedy hero has your back.
** On January 18, 2010 a large crowd of people gathered outside of Universal Studios in spite of cold, rainy weather to show their support for Conan. Turned into a MomentOfAwesome when Conan himself came running out into the crowd to hug, shake hands, literally jump around, tell the crowd to "Keep cool, my babies!" (the crowd went insane at this), lead them on a ''Rocky''-style run to the studio, then from the roof of the studio waved and performed an impromptu string dance which drove the crowd even crazier. Similar rallies were held in cities across America, most notably in front of 30 Rockefeller Center in New York.
*** Not only that, but he bought pizza for the entire crowd on account of them being in the rain so long.
* HilariousInHindsight: The "Twitter Tracker" skit parodied increasingly vapid celebrity tweets. [[http://twitter.com/ConanOBrien Guess who has a Twitter account?]]
** His first tweet is ten kinds of [[FunnyMoment hilarious]]:
-->"Today I interviewed a squirrel in my backyard and then threw to commercial. Somebody help me."
** Made even funnier when that squirrel [[http://twitter.com/ConansSquirrel started tweeting.]]
*** "Entertainment Weekly" declared Conan to be "[[TakeThat Funnier in 140 characters on Twitter than Jay Leno is hosting ''The Tonight Show'' for one hour.]]"
* MemeticMutation: "Coco", the nickname Creator/TomHanks bestowed upon him during the second episode of his tenure.
* TearJerker: Deon Cole reiterating during a sketch that Conan's staff loves him and is totally loyal to him, about a week before their tenure on the show was about to end.
** As well as Conan's speech to his audience on his GrandFinale. He told the audience that, as part of his settlement, he was allowed to say ''anything'' he wanted during the segment. He went on to thank NBC, his staff, his crew, his audience, his fans, and everyone who supported him. He advised his younger fans to shun cynicism and embrace kindness. And he did all this while choking back tears himself.
* TooGoodToLast: Thanks, Jeff Zucker!

!!Creator/JimmyFallon[='=]s incarnation (2014-Present) provides examples of:
* HilariousInHindsight: On Jimmy's first night, Stephen Colbert (host of Comedy Central's ''Series/TheColbertReport'', which airs opposite ''The Tonight Show'') was one of the many big stars to welcome him, dumping a small barrel's worth of pennies onto Fallon's desk and shouting, "Welcome to 11:30, [[ThisIsForEmphasisBitch BITCH]]!" It became a bit more amusing a few months later in 2014, when it announced that Colbert ''himself'' was moving to take over David Letterman's show on CBS. This meant that he was still airing at 11:30, but was now competing against Fallon on one of the main broadcast networks. Even better, Jimmy Fallon made a cameo on ''Colbert's'' first night on ''[[Series/TheLateShowWithStephenColbert The Late Show]]'', bringing it full circle.
* InternetBackdraft: His interview with Donald Trump wherein he tousles his hair inspired a lot of flack as to whether or not the show had a Pro-Trump agenda. Many other celebrities like Creator/SamanthaBee and director [[Creator/TheCoenBrothers Ethan Coen]] have accused him of supporting Trump and humanizing him, with the latter even going so far as to say Fallon was one of the people responsible for Trump's election.
* MemeticMutation: It's become a running joke in the comments section of the show's [=YouTube=] page of calling Jimmy out on his [[{{Corpsing}} fake laugh]].
* NeverLiveItDown:
** After learning that he had spectacularly bombed a blind date with Creator/NicoleKidman (in that he didn't even ''realize'' it was one), subsequent guests have reminded him of his EpicFail.
** Tousling Donald Trump's hair has quickly become this, and may have played a part in viewers abandoning the series in favor of ''The Late Show''. In a ''New York Times'' piece, Fallon himself [[https://www.nytimes.com/2017/05/17/arts/television/jimmy-fallon-tonight-show-interview-trump.html?nytmobile=0 admitted]] that the Trump interview was a "setback," and that he didn't do enough to address the controversy at the time.
* SomeAnvilsNeedToBeDropped: A sketch on one of the 2016 L.A. shows featured Jimmy as Donald Trump, anxious about his presidential campaign. The cast of ''Series/FullHouse'' gave him advice, with the best being that someone's job as president should be about bringing people together, not tearing them apart (which is what he's been doing with his "ban all Muslims from temporarily entering the U.S." and "build a wall across the Southern border" rhetoric, among many other things).
* SuspiciouslySimilarSong: The music accompanying "Random Object Toss" sounds similar to "Sweet Georgia Brown".
* TheyChangedItNowItSucks: The game "Pictionary" used to be played the traditional way, with markers and paper, but in late 2016 Jimmy showcased a new technology that allowed you to play a virtual reality version. Fine, except the classic style is no longer played ''at all''. It doesn't help that the drawings in the virtual reality version are sometimes harder to see, due to the contestants moving around (which, in turn, moves the picture).