The Chipettes have gotten more and more screentime overtime, to the point where the last episode Ruby-Spears (the first showrunning company, followed by DiC) had produced for the series doesn't have Dave or the Chipmunks themselves in it.
Starting as walk-ons in an unfinished episode of Space Ghost Coast to Coast called "Baffler Meal", the Aqua Teen Hunger Force stole the spotlight so thoroughly that the episode was rewritten without them, and the episode was repurposed as "Kentucky Nightmare". However, instead of scrapping those characters, writers Matt Maiellaro and Dave Willis decided to make the Aqua Teens the protagonists of their own show. When ATHF became popular, the writers decided to finish SGC2C's "Baffler Meal".
Maxine Gibson. As Terry's Secret Keeper, she is involved in both his civilian and superhero lives; as a consequence, she takes the screentime of both of Terry's supporting casts. It's most noticeable with the decreasing prominence of Terry's family and Dana, his girlfriend, in the later seasons, and the number of episodes that barely feature Bruce Wayne or leave him out completely.
On the villains' side, Blight, which you could think would be the Big Bad due to murdering Terry's father and leading him into becoming Batman, is tied with various other rogues for number of appearances. While he technically still appears the most if you count his earliest appearances as Derek Powers, after becoming Blight, he just vanished, with a line from Terry implying he's ran into Blight ocasionally offscreen. Stalker is tied for number of appearances with Blight (two) despite seemingly dying in his first appearance, and Inque has five appearances, beating both of them by quite a mile. To rub salt into the wound further, Stalker got two more appearances in the tie-in comics, one of which dealt with him hunting Blight. Ditto for Inque.
According to Word of God, this was the reason Ben 10: Omniverse had Ben's alien form Jetray removed and his teammates Gwen and Kevin Demoted to Extra: the former, due to being the second most regularly used alien form, was considered as stealing screentime to other alien forms, and the others were considered as taking too much focus of the show when the writers wanted to focus on Ben himself. A lot of fans have been quick to point out the fact that in the end, Ben's new partner in Omniverse, Rook, ended up actually stealing even more Ben's screentime than Gwen and Kevin ever did, and the one alien who actually appeared the most, Humungousaur, still appeared several times in Omniverse.
A lot of episodes of Beverly Hills Teens are focused on Bianca (the resident Alpha Bitch), to the point that some sources list her as the main character.
In Season 2 of Castlevania the story shifts focus from the heroes Trevor, Alucard and Sypha to focus on Dracula and his Co-Dragons squabbling, betraying and delving into their respective backstories all while the Power Trio is literally stuck in a library for most of the Season. This gets redeemed in the Final Battle where the heroes return in force but it's still quite jarring.
Season 3 plays with this as while Alucard is benched with his own story thats separate from rest, Battle Couple Trevor and Sypha get the main focus as well as Issac with his own adventure. Both Trevor and Sypha and Issac's stories overshadow the plot lines of Carmilla, her Co-Dragons, Hector and Alucard.
Because of the Care Bears being the result of a greeting card and Merchandise-Driven, you can count on one hand the number of episodes that haven't been centered on either the bears who actually wore clothes or Brave Heart Lion. And you can count on one hand how many times Loyal Heart Dog even spoke, let alone had his own episode.
Elise in Dan Vs. could be considered this by many fans of the show since by the second season, most of the episodes focused more on her, thus distracting the main plot of Dan's revenge schemes with Chris tagging along in the adventure, and a lot of Dan's schemes are solved by Elise herself, causing an unfortunate case of Deus ex Machina on Elise's part, which is why the fans considered it a Seasonal Rot. This seemed to die down a bit by the third season though.
The Dreamstone was initially designed with Rufus as the main protagonist, with early concept work using the Urpneys as more minor comic relief. In the pilot episode, the Urpneys are upgraded greatly and given individual personalities and spotlight, however Rufus is still played as the main hero and gets the majority of genuine Character Development. Following this he is diluted into a Hero Antagonist and the Urpneys act as the Villain Protagonists for most of the series. Even their boss Zordrak usually only appears in "bookend" appearances for each episode.
Seasons Three and Four downplayed the Villain Protagonist dynamic slightly, and started to even out the focus between Blob's squad and Rufus and Amberley. Zordrak and most other regulars such as the Wuts remained as Out of Focus as ever though.
DuckTales: The second season of DuckTales (1987) introduced Fenton Crackshell/Gizmoduck, a clear Expy for the absent Donald Duck, who would go on to either star or co-star in almost every episode of the second season, causing many other previously prominent characters such as Launchpad McQuack and even to some extent Huey, Dewey and Louie to be moved Out of Focus. Only Scrooge himself remained as prominent as ever. Unlike other examples of this trope, though, Fenton is fairly popular with the fanbase, possibly thanks to his dual status as Butt-Monkey and Superhero.
GIR in his puppy suit from Invader Zim has dominated the most attention, even more so than the title character himself, appearing in Hot Topics nationwide. The puppy suit in particular has almost completely eclipsed GIR's true robot form, even though the robot form had more actual screentime in the show. Like the example above, GIR is popular with the fanbase.
Since Season 7 onward, Denzel Crocker, Timmy's dad, Cosmo, and Foop from The Fairly OddParents have more and more amount of screen-time in the series, ESPECIALLY the two former, in detriment of the main characters in the earlier seasons, like Chester, A.J., Tootie, Trixie Tang and Vicky, the latter of whom was the main antagonist for the majority of the series.
Season 10 takes this up a notch, and now Crocker appears every episode (strangely, his obsession with fairies is gone). He even gained a nephew who appears a couple of times (and he's basically just a younger version of Crocker). This went to the point that Poof and Vicky, formerly major characters, only have one and two appearances in the season, respectively.
Family Guy may as well just be "The Brian and Stewie Show" in later seasons. Peter hasn't really suffered from it, but Chris and Lois have (whereas Meg's been Out of Focus for most of the show). More and more episodes are about Brian dating someone and the 150th episode special is completely about Brian and Stewie being trapped in a bank vault. In fact, said 150th episode was simply called "Brian and Stewie". They are the main characters of the 200th and 300th episode. Let's face it, it's all about them now. Not to mention the "Road To..." episodes, which focus on Brian and Stewie entirely. Another example of this would be the episode "Not All Dogs Go To Heaven", where Peter flat-out states that this was a "Meg episode" and that he wouldn't blame the audience for changing the channel... the episode was actually more about Brian. The two also double as Wolverine Publicity (especially Stewie, who would appear in practically all of The Merch early on).
In addition to that, almost every episode that didn't have him as the main character had him in a subplot, two of the movies had his name in the title (Bender's Big Score had more to do with Fry and Leela), and the two that didn't had very long subplots involving him.
Amy and Hermes are easily the most underused characters in the series. Season 6 tries to correct this by having one Hermes episode and two (!) Amy episodes. The catch? Both the Hermes and one of Amy's eps are centered on Bender.
Even happens in-universe. He gets a minor spot on "All My Circuits" and quickly steals the show.
Kaeloo might as well be called "The Mr. Cat Show". Pretty much everything revolves around what he's doing, and he is focused on even more than the show's protagonist, Kaeloo.
The The Land Before Time TV series reintroduces Chomper as a main character, who proceeds to hog the spotlight for most of the show. Most of the episodes center around him, and even in episodes that feature the return of other popular characters (such as Ali and Mo), Chomper still seems to get a B plot to focus on him.
Varrick gets an incredibly large number of screen-time come book 4. With a handful of small cameos in book 3, for the final season he took center-stage and it is noticeable. Many fans agree that as entertaining and funny as a character he is, the fact he got more focus, development and screen-time compared to characters such as Mako or Asami (who are two of the main characters) is a bit overbearing considering that it is the final season of the show.
Korra has a recurring problem with this trope due to having a huge ensemble cast with plenty of darkhorses. Season 1 Lin Beifong become a fan favorite and was heavily focused on, getting a huge amount of the A Plot. The beginning of Season 2 focused on Tonraq and the second part developed Jinora. Season 4 might as well be called the Suyin and Beifongs show due to their heavy focus.
The Lilo & Stitch franchise is very hyper-fixated on the latter title protagonist himself. Stitch is so popular a character that since 2008, Disney has released several spin-offs that focus more on him and reduce Lilo Pelekai's appearances, with the Stitch! anime having her appear in only a third-season episode as an adult, Stitch & Ai only having her appear in brief flashbacks (with Stitch not even remembering who she is), and Stitch & the Samurai outright removing her altogether (since it takes place centuries before her time). The franchise's merchandising front has such little character variety—especially for a beloved franchise that's all about ʻohana with its quirky yet charming characters—that it's gotten to the point that in 2021, Disney has quietly rebranded the franchise to just his name, driving the point home that Stitch is the franchise, no ifs, ands, or buts.
The Looney Tunes Show might as well have been called "Daffy Duck and Friends", as, with the sole exception of "Ridiculous Journey", every episode is either focused on him or features him as an important part of the story. Even calling it "The Bugs and Daffy Show" is pushing it a little, as Bugs is often reduced to Supporting Protagonist. It gets to the point where most of the other characters, aside from Bugs, Lola, Tina, and Porky, are all but forgotten by the second season.
My Little Pony 'n Friends episodes switched protagonists every few episodes, but it still had a few members who appeared often. Among them were Fizzy, Lickety Split, Surprise, Gusty, and Wind Whistler. In a Merchandise-Driven series with 100+ characters, this is reasonably apparent.
During season 6, most episodes where Starlight Glimmer showed up ended revolving around her and she has been featured prominently in all the season premieres/finales since her introduction, even supplanting the Mane Six entirely during the Season Six finalenote A grand total of 12 appearances as of Season 7, most of which are in starring roles. She even manages to play a critical role in the third animated special of My Little Pony: Equestria Girls Magical Movie Night, "Mirror Magic", where she controversially steps over resident series focal point Sunset Shimmer. It got to the point that "Starlight Episodes" were so detached from the rest of the show and other characters that they could be outright skipped without missing a thing (which might have been intentional, given how controversial a character she is). Season 8 largely bucked this trend, giving her only two focus episodes and even a number of Take Thats in episodes like The Mean 6 and Father Knows Beast, and she was almost entirely absent in Season 9, save for two Standalone Episodes and a few brief scenes in a few other episodes.
That said, seasons 8 and 9 have largely demoted Starlight to extra to make room for a new literal squad, the Young Six. A group of students at Twilight Sparkle's new school who collectively took up a solid third of Season 8, including having prominent roles in both the premiere and finale, and a large chunk (albeit less than the last season) of Season 9.
Mindy Melendez from Ready Jet Go! became this big time. She was created for the sole purpose of representing the younger members of the target audience, and she turned out to be highly successful and popular with the show's fans. Even though she received equal screen-time to the other characters in Season 1, by the time Season 2 premiered, most of PBS' marketing revolved around her specifically, and she takes up the majority of the screen-time in any episode she's in, often playing a big role of some sort (such as advising Jet to use the battery in "Racing on Sunshine"), all because of how much she resonated with the kids watching at home. This is despite the fact that Mindy is a Flat Character with not that much personality traits, and her constant focus has swept other characters who are more interesting than her such as Sydney, Carrot and Celery, Face 9000, Dr. Rafferty, Dr. Bergs, Mitchell, Lillian, and even Uncle Zucchini to the wayside.
Muscle Man from Regular Show slowly became this. Almost every episode in season 4 featured him in a major way. He also appears in almost every preview for an episode, even if it did not feature him majorly. What's worse, his partner High Five Ghost, had received no Day in the Limelight episode after Season 4 began until "The Postcard". He did get a few episodes of his own since then, but Muscle Man had a major role in all of them.
Lady Gaga in the Season 23 finale. Not only did she appear on screen before any Springfieldian, she actually got more screentime than the Simpson family. Naturally, this didn't endear her to any Simpsons fans who aren't Gaga fans.
As the show went on, Moe had been getting a noticably increased number of episodes focusing on him. This was mainly to prevent Hank Azaria (his voice actor) from leaving the series, but it did turn him into a Base-Breaking Character.
In Sonic the Hedgehog (SatAM), Princess Sally leaned more and more into center stage to the point only she and Sonic seemed to have involvement in the majority of missions. Antoine was also prominent comic relief, even gaining four half-sized episodes devoted to his slapstick role, along with often being brought along on otherwise Sonic-and-Sally-only missions, despite functionally being The Load.
Additionally, Dulcy the Dragon, introduced in the second season with no explanation and quickly became one of the most prominent Freedom Fighters, essentially becoming their only mode of transport from then on.
Randy Marsh from South Park became this as time went on. In fact, the most recent seasons seem to show that he has dethroned the boys as the main character, with Stan and Kyle being mostly Out of Focus and Kenny being Demoted to Extra. Cartman is this as well, although that has been the case since day one (the first episode is titled "Cartman Gets An Anal Probe"). It gets to the point that South Park might as well be "The Cartman & Randy Show" nowadays.
Around Season 22, the show has largely focused exclusively on Garrison, Randy, and PC Principal. Even Cartman has been relegated to a background character in some episodes.
SpongeBob SquarePants might as well be called the "Mr. Krabs vs. Plankton" series featuring SpongeBob, Patrick, and Squidward due to the unhealthy amount of focus with them since Season 6; most notably Mr. Krabs. It doesn't help that most of the recurring characters get less focus in favor of those two as the seasons pass by. This has largely died off as of the second half of Season 9, however.
Rabbit gets a lot of focus as he is the most fleshed out, having plenty of episodes focused on or set around his house and garden. He is pretty much The Leader of the main cast, usually taking the reigns on their latest misadventure.
Gopher is made a main cast member by this series, with many episodes devoted to havoc he wreaks with his latest construction project, especially towards the end of the series. He appears more frequently than Eeyore, usually considered to be the fifth main cast member besides Pooh, Piglet, Tigger, and Rabbit.
Tiny Toon Adventures: Acme Looniversity actually has a Spotlight Stealing class (taught by notorious Attention WhoreDaffy Duck). Plucky, Buster, Babs, Hamton, and Elmyra must have done especially well, considering how much focus they got. Elmyra would later be shoehorned into Pinky and the Brain as well as Animaniacs; in the latter, she's called into a group counseling session with the Warner siblings. They con her into following Mindy. Yes, that Mindy. Buttons gets a day off.
Duncan, Heather, Gwen, and Owen have the highest episode counts out of all of the contestants in the series. All four of them made it to the final four in the first season without returning, Duncan and Owen have also been some of the few contestants to return in the game. All four of them were also finalists, which means that in certain countries, they were picked as that season's winner. Although Owen's is far lower thanks to him not competing in All-Stars. note Unless you count his appearances on the Ridonculous Race, which would give him the most screen-time out of all the contestants in the series.
Courtney also received a lot of focus throughout the series, especially when the Love Triangle between her, Gwen, and Duncan took center-stage in World Tour, and later, Gwen's ultimately failed attempt to reconcile with her in All-Stars.
Cody, who had not one but two subplots during World Tour, doubling his screentime.
In World Tour, newcomers Alejandro and Sierra receive a lot of focus, especially when they interact with any of the aforementioned Spotlight Stealers. It did not help when it became gradually obvious that Alejandro was Heather's long awaited canonical love interest, while also serving as the Big Bad of World Tour.
Zoey has had the most screentime of any second generation cast member, receiving ample focus in both Revenge of the Island and All-Stars. Her being in the spotlight is particularly strange in that she spends most of Revenge as a Satellite Love Interest and does not contribute anything to the plot of All-Stars until the very end of the season.
Scott is also one the more focused on second-gen contestants. It's justified in Revenge of the Island since he was the main antagonist of that season; however, in All-Stars, he only lasted as long as he did to serve as the season's main Chew Toy and to serve as a Satellite Love Interest for Courtney.
Cameron was also hit by this to a lesser extent, having been one of the main protagonists and ultimately a finalist in Revenge of the Island and later returning in All-Stars. It took a turn for the worst though in All-Stars as he becomes the new subject of Sierra's obsessions and dodges multiple eliminations, only to end up as dead weight for much of the season.
As of All-Stars Mike has also been hit with this status, with his multiple personalities receiving more spotlight than Mike himself (particularly villainous alter-ego Mal). His friendship with Cameron and relationship with Zoey also further exacerbates his Spotlight-Stealing status.
Shawn and Jasmine in Pahkitew have substantial focus throughout the season due to their Ship Tease with each other and their respective friendships with Dave and Samey. About Shawn, considering he's also a finalist, this makes him the overall the most focused on contestant in Pahkitew Island.
Sugar has made more enemies than any other contestant in Pahkitew Island, and is the most focused on antagonist this time round. As well as frequently stealing the show with gross-out gags in a manner similar to Owen.
Sky is also one of the more focused on third-gen contestants, due to her Unresolved Sexual Tension with Dave pre-merge and her rivalry with Sugar post-merge.
The Ice Dancers and Police Cadets in Total Drama Presents: The Ridonculous Race. The first are the most focused on pairing, placing no worse than third in the first eight episodes, and they're the Big Bads of the season. Not to mention that Josee and MacArthur have a major rivalry throughout the season.
Emma and Kitty also. They have had quite a lot of focus, especially on Emma's attitude towards Kitty, and that's before Emma's romantic plot with Noah.
Total DramaRama continues the tradition, despite not being a reality show with eliminations and having a reduced cast size. Chef has roles in every single episode due to being the kids' teacher in this series, but most episodes focus on Duncan, Owen, Izzy, or Beth (with the first two already known for being major Spotlight Stealers in the main series).
Transformers: Prime has had two episodes devoted entirely to Arcee and Jack, with the other Autobots and kids not showing up for longer than a quick silent scene at the end. Much better than the other partners, as Raf and Bumblebee only had focus in one episode so far, and they had to compete with a B-plot with the other bots stopping Starscream. Miko and Bulkhead fared better mostly due to Bulkhead's rivalry with Breakdown, but they still needed to compete for screen time with other characters. Meanwhile Ratchet barely leaves the base, while Optimus Prime himself usually just shows up at the end of the episodes to kick ass, if the two aren't absent entirely. Meanwhile Arcee appeared in every episode of the series until roughly mid-Season 2, appearing the most out of any character. This is refreshing however, since generally female Transformers are minor characters that don't do much/lack focus. It helps that Arcee has given much more backstory than most of the bots in form of animation rather than frames like Bumblebee's or just mentioned like Bulkhead and Wheeljack's.
For the villains, Starscreams struggles to take power take quite a bit of focus during the first and second seasons, to the point he could be considered a tertiary Villain Protagonist.
By Season 3, however, Arcee and Bulkhead are both Out of Focus, with Ultra Magnus and Wheeljack getting the first major arc of the season; then Ratchet as he becomes critical to the events of the series finale.
Fans generally love Blue Beetle and Impulse, but it's hard to deny that they got a lot more attention than the other season two newbies, let alone the main six from season one. Justified by their comparative importance to the plot in a rather extensive cast, but still, couldn't they sacrifice one or two of their episodes to give Batgirl something to do?