The BronyismFacebook page. It used to be a hub for loyal fans of the show until a team of Trolls hijacked it from the unsuspecting admins on December 14, 2011 and turned the place upside-down, replacing the ponies with obscure memes, bizarre stories and images, off-the-wall religious and political debates, odd Toilet Humor, and the like. Subverted as of March 26th, 2012, it is once again a home for the show-loving bronies.
Played for Laughs in Girl-Chan in Paradise by Egoraptor, which barely features its eponymous character. Even when the characters are standing in a group shot, don't expect to see her anywhere in sight. In the ending theme sequence, she's the last of the floating head lineup to appear. Yusuke even goes so far as to say implicitly that she's worthless and to tell her to shut up when she gives her one line for the entire episode.
The name "lonelygirl15" made a lot more sense when it was a girl in her bedroom talking to a webcam. Especially after they killed off the title character.
In Sockbaby Part 3, Sockbaby's plot was wrapped up, and he left for heaven or another universe or something. He doesn't appear at all in Sockb4by, which just focuses on the further adventures of Ronnie and Burger.
Other than being her TGWTG handle, have you ever heard The Nostalgia Chick being called her username of "The Dudette"? Even the url on the website was changed to "Team N Chick".
The title of The Joker Blogs originally referred to The Joker's treatment tapes at Arkham Asylum being put up on YouTube (something the Joker planned to occur) in a 'blog' format, occasionally featuring updates with tasks for the 'goons' (fans) to do. As of the end of the First Season (around the start of the "Find Patient 4479" arc words), this is no longer the case since the episodes afterwards are in less of a 'blog' format and focus more on the plot.
Barney Bunch was originally made when Barney hate was still at large, but soon coming to an end. Today, most Barney Bunch videos feature Drew Pickles as the main character instead.
The first Demotivational Posters were cynical parodies of motivational posters, bearing messages about your inevitable failure. Following Memetic Mutation the same style of image is now used essentially as a one-man caption contest, keeping the name but rarely trying to demotivate.
Marble Hornets. The eponymous student film arc has been over since about entry #20. It gained prominence again in roughly entry #53, but considering where the plot has gone, this is likely a temporary thing.
The International Broadway Database can't exactly be international if Broadway is only in one place. But it was probably titled this to imitate imdb.
Red vs. Blue hasn't had the Red and Blue characters as actual enemies for a while, although most of the humor comes from their failed attempts to kill each other.
Most of the characters on the Red and Blue teams were never either strictly red or blue anyway—Tucker is teal, Simmons is maroon, Grif is yellow orange, Tex is black, Lopez is brown, and Donut is pink "lightish-red". Since Season 3 or so, the plot has had virtually nothing to do with Reds versus Blues (although it's still mentioned, and the Red vs. Blue "war" is technically an important piece of the story, even if the main characters no longer participate in it), instead being about a bunch of people with armor colors nowhere near red or blue (all of the Freelancers, for example).
Also, the original subtitle (Blood Gulch Chronicles) is rather inappropriate for the large amounts of time they spend away from Blood Gulch, particularly in Season 4. Averted later when they changed the subtitle when they permanently left Blood Gulch after Season 5.
Rooster Teeth's Achievement Horse series hasn't involved any actual games of Horse in a long time, the competitors usually opting to play shorter games of Pig.
Master Chief Sucks at Ordering stops being about Master Chief sucking at ordering things after the third episode. However, the series (and its episode titles) continue to reference the fact that Master Chief sucks at doing things. The reason the show wasn't simply called "Master Chief Sucks" to avoid this problem was presumably because another series already used that name; said series would then be permanently renamed to Arby 'n' the Chief.
That Guy with the Glasses started out as a website where internet comedian/reviewer Doug Walker uploaded all of his videos before other content-creators started contributing to the site.
His main series The Nostalgia Critic originally focused on "nostalgic" movies and television shows from the 1980s and the 1990s (hence the title). Since the 2013 revival of the series, the date limit has been removed and the show has become more of a general review show, though still with a bent on relatively "older" films up to at least the mid-2000s.
Text riff series I Can't Believe It's Not AVGN! started out with bad AVGN clones (notably The Irate Gamer, Game Dude and NC 17 Productions) but has expanded to just bad video game reviews in general. The title stayed.
The Happy Video Game Nerd was originally named as such as he was a parody/inversion of The Angry Video Game Nerd, reviewing underrated retro games with a positive tone if overenthusiastic tone. Nowadays, he also includes modern games and more mainstream titles, and has done away with the "happy" in favor of more natural and objective tone.
How It Should Have Ended started off showing parody alternate endings of movies. The focus has since expanded to more general movie parodies, featuring scenes from much earlier in the movie and sometimes not even touching the ending at all.
Some people choose usernames that reference a series, then later on disown the series, especially in fandoms with poor reputations.
David Mitchell's Soapbox was originally a pun on the fact that it was sponsored by a brand of men's cosmetics. They withdrew their sponsorship at the start of the third series, but the title remained.
For a more general example, football forums have had Adaptation Expansion and football is only part of their schtick/USP; it still remains, probably due to the Grandfather Clause, but the term is an otherwise artifact title in general.
Although anyone can still upload documents, WikiLeaks stopped allowing people to edit them afterwards a long time ago, so it's no longer truly a wiki.
Some blogs on SB Nation, most notably the Toronto Maple Leafs' Pension Plan Puppets - it referenced how the Ontario Teachers' Pension Plan owned most of the team's parent company, but they have since sold their share. One at least confesses the nostalgia outfront: the Washington Wizards one references the team's previous name, Bullets Forever.
Barely Political is actually an inversion. Back when it became popular in 2007, it made nothing but political videos in time for the 2008 election season. Now, six years later, it's become a Meaningful Name, as most of its videos are Key of Awesome parody videos.
Stupid Mario Bros was originally a nonsensical comedy with no real plot. It was mostly just characters from Nintendo games in the real world while engaging in slice-of-life activities. When they decided to add more elaborate story arcs, the show became a lot more dramatic and less "stupid".
Retsupurae is an Engrish pronunciation of the words Let's Play, refering to what they originally made fun of.