Anything goes on the Internet when it comes to user-posted content. Anything.
This episode of a Wheezy Waiter, a video blog series, has one. Before Wheezy Waiter actually starts talking, he makes a bunch of bizarre 'WHOOOOOOP' sounds, gnashes his teeth and makes a series of faces. It's bizarre, it has nothing to do with the topic of the video, and after it happens he never speaks of it again (except one small comment on it right after the scene)
The Nostalgia Chick makes reference to this in The Nostalgia Critic's review of FernGully, and even pulls a few of them herself during the review such as interrupting a joke about Tim Curry to break out an accordion and play it with no relevance to their discussion or the movie. (Which, since this is where the trope and the name first came together in one place, they gleefully lampshade.)
In the Critic's review of the Arnold Schwarzenegger/Danny De Vito film Junior, an elaborate dream sequence music video illustrating how boring the movie comes up. The Critic only continues the review because Bhargav sentences him to seeing a baby with Arnold's head whenever he sleeps, until he finishes the review. This sequence takes up a good three minutes of the eighteen minute video. Upon waking up, he apologizes to the audience and asks that they get the labeling of the Big Lipped Alligator Moment over and done with.
The Critic points out in his "Top 11 Mindfuck Moments" video that many of the scenes he mentioned could be considered a Big Lipped Alligator Moment.
A BLAM has actually been used by the Nostalgia Chick in combat, as she invoked one in the Anniversary Brawl to save herself from Little Miss Gamer and The Aussie Guy, before punching them in the gut.
For recursion points, the Big Lipped Alligator Moment meme gets treated as a Big Lipped Alligator Moment once. In the Nostalgia Critic/Linkarajoint review of Superman IV, the Critic invokes the meme in response to a scene of Lex Luthor dancing with a woman in period dress. Linkara gets weirded out and the Critic, noticing his confusion, says "I don't know, the Nostalgia Chick came up with it."
Also, in the Critic's We're Back review, the crows apparent 'eating' of Screw-Eyes is met with an announcment as a BLAM.
One that seems to go unnoticed is The Lord of the Rings reference in his Captain N review, where Nostalgia Critic has a flashback to when Mario stealing some kind of power when he was supposed to "cast it into the fire". It comes right out of nowhere, has virtually nothing to do with the review, is completely over the top and ridiculous, and he never brings it up again.
Oh, and Rob is a Dinosaur. For no reason. Several times.
Professor Otaku began ending his vids with these after his Street Fighter review, and has been fairly consistent with tagging them onto the end of his videos. However, lately, he seems content to simply use the footage without additions.
In The Angry Video Game Nerd's review of Moonwalker, right at the end (after throwing a fit of explosive proportions), he turns into a cat, and then pads off. That Michael Jackson did the same on his "Black or White" music video doesn't make either case any less strange.
Likely was making fun of the music video and Michael Jackson due to the insanity of the game and the BLAM. So in this case it would be a BLAM referencing a BLAM.
Also, during his Star Wars review, a buffalo actually takes a dump right through the Nerd's window, during his big list of Star Wars games he didn't get a chance to review. Possibly a reference to his Theme Song.
RedLetterMedia's Star Wars reviews are kinda fragmentary to begin with: their shtick is that the reviewer is psychotic, and sloppily taping reviews over his home videos (mostly about torturing prostitutes, how's that for Comedic Sociopathy?) There's still the scene in his basement where a tiny black droid floats in, looks at the two women there, and flies away. They stop struggling to blink.
Awkward has a musical number entitled "Miss Brighteyes" that's about Lester's feelings for Steph, Alex's feelings for Lester, masturbation, and crossdressing. It comes out of left field, is never referred to afterward, and could be removed entirely without affecting the series. But it is pretty hilarious.
The Motley Two has a sudden scene shift to "Troll Cuba", where Troll Fidel Castro and Troll Hannibal are getting into shenanigans, all borne out of a throwaway phrase about cigars.
Homestar Runner has an unique twist on this trope: the big-lipped alligator character named Homsar. Homsar is basically a deranged, reality-warping copy of Homestar who speaks in wails and non-sequiturs whenever he makes an appearance, and barely anybody elaborates on it. Probably his best example of big-lipped alligatory is his easter egg appearances in the Halloween toons, which are triggered by clicking on The Poopsmith in a certain scene.
An early episode of Yugioh The Abridged Series starts with an ad for Yugiohs. They're Yugilicious. It's weird even for the genre it's in.
In We Are Our Avatars, Genghis Khan used to pop out of nowhere just before the thread was moved to RP.
Earlier, the Anti-Spiral appeared and forced the cast to do the Caramelldansen.
A Death, Tails, Osaka, Mega Man and two different Tenshi Hinanai play a game of Battleship, which Death turns into one awesome game, Tails even lampshades the trope.