Char's Counterattack: Novel (Hi-Streamer) → Movie → Novel (Beltorchika's Children). Note that both novels were written by series creator Yoshiyuki Tomino, and none of these are straight adaptations.
Dragon Ball Z had a double recursive adaptation: the fourth Dragon Ball ZRPG for the Family Computer was titled Dragon Ball Z Gaiden, which featured a new storyline written specifically for the game. A two-part video guide for the game was then released that was essentially a Dragon Ball ZOVA with footage of the Famicom game spliced in between. The animated segments of the video guide were then reused for two FMV games released for Bandai's short-lived Macintosh-based Pippin game console in Japan.
Dragon Ball Jump Festa special, Yo! Son Goku and His Friends Return!!, was adapted into a one-shot manga by Ooishi Naho.
The Dragon Ball Z TV special Bardock: The Father of Goku featured an original storyline that wasn't in the original manga, years later Naho Ooishi wrote a manga miniseries called Dragon Ball: Episode of Bardock set after the events of the TV special. Episode of Bardock is now getting an anime adaptation. That makes it an OVA adapted from a manga which is a sequel to an anime TV special which was spun-off from a manga. Also, just to make it more confusing, Bardock as a character received Canon Immigrant status in a flashback in Toriyama's original manga.
Also behold Ghost in the Shell: Stand Alone Complex: Solid State Society, the movie based on the anime based on the movie based on the manga.
Lupin III is a multi-media franchise that began as a serial manga. After making its way to Anime, some of the stories have become full-colour manga volumes.
Comic Souris has made full-colour manga from: The Castle of Cagliostro (a three-book set) and Lupin III (Green Jacket) (Volumes 2 through 12). The best example of recursion is when a Green Jacket episode was aired based on a manga chapter, and turned into a manga volume.
One Piece had a video game adaptation that had an original story, and the story of the game later got adapted into a Filler arc in the anime.
Trigun is a strange beast; it began as a manga, which ended prematurely due to publication issues but shortly after was adapted as an anime with a definite conclusion to the story; but later the original manga was republished under a different magazine, and continued on while borrowing story elements from its own adaptation.
Just about every comic book-based film has been adapted back into a comic book.
A trend that oddly started with Saga of the Swamp Thing Annual#1, adapting the 1982 film. (Due to scripter Mario Puzo's contract, no direct novelization or adaptation of the first two Superman films appeared.)
Super Friends goes an extra step. Comic → Toys → Cartoon → Comic. And it's adorable and fun.
Even weirder is that DC once had a comic based around a Bruce Timm-inspired animated world with its own version of Superman, Justice League, etc. This was before Superman or Justice League Unlimited but seemingly taking place in the world of Batman: The Animated Series. So it was a comic series based on a cartoon that would later have its own cartoon equivalent anyway.
Special mention must be made for the Young Justice / Teen Titans loop: YJ was a popular Lighter and Softer comic, which was adapted thematically into the TT cartoon, which got a comic book version drawn by the former artist of the YJ comic. Now, there is a YJ cartoon based on the Darker and Edgier TT comic, which has, in turn, gotten its own comic book adaptation taking place before and between episodes of the toon which, in turn, has several episodes written by the writer of the original YJ comic. Wheels within wheels, folks...
To add to the confusion, the TT cartoon was spun-off into a new comedy series, Teen Titans Go!. Which ended up getting it's own comic book adaptation. Meaning that it's a comic that went to a cartoon that went to a comic book that went to a cartoon that went to a comic.
There is a comic book which is officially Smallville Season 11.
DC typically uses their comic book adaptations of their animated shows to produce G-rated stories about their characters for kids (which are normally written at a PG-13 or above level for the aged 18 to 30 demographic that has emerged over the last few decades.) Similar to the Marvel Adventures line.
And Marvel has X-Men Adventures, and a very shortlived X-Men: Evolution comic. Basically, "Adventures" in a comic book name is a sure sign that you're reading the comic of the show of the comic, but not all of them will have "Adventures" in the name.
There's also comic book → first movie → comic book adaptation written and drawn by the original creators, resulting in the slightly weird case of the Turtles looking just like they do in the Mirage stories, but behaving like their movie counterparts (ordering pizza, for example).
In a slightly different case, the plot of the Ultimate Spider-Man game was adapted back into the comic as the "War of the Symbiotes" Story Arc.
Metropolis is a borderline example. It started out as a movie, then the Astro Boy guy made a manga that was inspired by briefly glancing at the poster, and then someone made a feature film out of that — which actually resembled the original film more than the manga did, as it heavily emphasized the elements of the manga that were already coincidentally similar to the film.
If you guessed this has happened to any of the Live Action Adaptations to Dr. Seuss' books, give yourself some green eggs and ham!
The Thing (1982) also had a novelization... making it a novel based on a film based on a short story (ignoring the previous film version of the short story which had little to do with the original).
Hollywood producers offered Philip K. Dick the chance to write the novelization of Blade Runner, itself a loose Film of the Book (the screenwriters had not read the original book) of his Do Androids Dream of Electric Sheep?? They would have paid a lot of money to do this, but, feeling insulted he refused. This led to the release of tie-in editions of Do Androids Dream of Electric Sheep? re-titled and looking for all the world like Blade Runner novelizations. Later, when his short story "We Can Remember It for You Wholesale" inspired the movie Total Recall (1990). Having gone through Development Hell and many screenwriters, the script was essentially an original script with even less in common with its source material than Blade Runner. By the time of the film's release, Piers Anthony had written a novelization of Total Recall. The novelization came out in 1989. The movie came out in 1990.
Black Beauty, originally a novel, had a movie made out of it. And then the movie was novelized into a children's book with pictures from the movie in the middle.
Several movies based on children's books wind up getting adapted into children's books again. Recent examples include Inkheart and The Tale of Despereaux.
Anthony Trollope's six-volume Palliser series (long) was adapted into a twenty-six episode miniseries (also long) only to be novelized again in a single volume (very, very short).
Fritz Leiber adapted Tarzan and the City of Gold starring Mike Henry into a prose Tarzan novel. He took pains to footnote past Tarzan adventures by Edgar Rice Burroughs to make this a canonical continuation of the Tarzan continuity of Burroughs.
Star Trek: The Animated Series example: the episode "The Slaver Weapon" was adapted by Larry Niven from his own original (unrelated to Star Trek) short story "The Soft Weapon". The episode itself was then subsequently novelised by Alan Dean Foster as a Star Trek novel. This means that there are two print versions of the exact same story, both of which are similar but also startlingly different from each other.
Many The Saint comic strip arcs and TV episodes received prose adaptations by Leslie Charteris and other writers. These adaptations fit into the Saint's literary continuity. Examples include The Saint in Trouble (has a footnote to the events of The Last Hero) and Salvage for the Saint.
Will Murray wrote some Remo Williams comic books, at least one of which he adapted into a prose novel.
Max Allan Collins wrote a Bones novel. This counts as a recursive adaptation as the Bones TV series adapts Kathy Reichs' concepts from her novels.
Carl Dreadstone adaptations of the Universal, many of whom started in prose.
The novelization of Tim Burton's Planet of the Apes remake was a novelization of a remake of a film adapted from an English translation of a French novel. Yikes.
Joy Hakim's A History of US middle-school textbook series was adapted into a PBS documentary series Freedom: A History of US, which was released concurrently with a history book (not quite written for middle-schoolers, but for all casual readers) adaptation of the documentaries, sharing the revamped title with the documentaries. So Textbook → Documentary → history book.
The Magic School Bus series had books based on the TV series based on the book. They were by far the least educational of the versions.
Both Arthur and Franklin began their lives as popular book series. Both have since been made into television series. In turn, episodes of those series have been released as books, though they've generally avoided releasing episodes as books that were adapted from books in the first place.
The Goosebumps series by R.L. Stine was adapted into a TV show, which then was adapted back into books based on the episode (though, these books were written by someone else).
Moonraker has an interesting history as a book → movie → book. It was the third James Bond novel by Ian Fleming. It was then adapted into a film in 1979... but the film only incorporated the villain (Hugo Drax) and the idea of a rocket from the novel. The screenwriter, Christopher Wood, adapted his screenplay into a book of the movie, titled James Bond and Moonraker to differentiate it from the original novel.
Mary Roberts Rinehart adapted her detective novel The Circular Staircase in collaboration with Avery Hopwood into the play The Bat, whose runaway success led to a novelization.
The Fox and the Hound, a novel by Daniel P. Mannix, and obviously literature to begin with, was very very loosely adapted into a Disney movie which was then further adapted into another series of books.
Nearly every popular animated movie has a children's book version, including movies that are based on books or stories.
Conan the Barbarian, both the 1982 and 2011 versions, received novelizations. (Admittedly, an unusual entry, since the films did not especially specifically adapt the tales from the 1950's reprint volume Conan the Barbarian.) Robert Jordan also wrote a novelization of 'Conan the Destroyer'', but no anthology or novel had used that title.
Significant changes were made to A Princess of Mars to get the movie John Carter, but at least the novelization included the original novel as an added feature in the back of the book!
The first Jurassic Park film was based fairly directly on Michael Crichton's novel, though differed in several major respects – including just which characters survive or not. Crichton's subsequent book The Lost World was written more as a sequel to the movie, rather than the novel, given the sudden Unexplained Recovery experience necessary for one major protagonist to appear after his apparent fate in the original novel. This new book was itself swiftly followed by a movie of (partly) the same name, although adapted more loosely still. A second sequel movie was then produced titled Jurassic Park III, combining some characters from the first book/film with the setting of the second and at least one major inspiration (the pterosaur 'cage') from the original novel. By the time we got to the third movie we're 4 steps away from the original book in general, though.
Pretty much any fairy tale that Disney adapted was later released by them as either picture books, a movie novelization, a manga, or all of the above, including Beauty and the Beast, Sleeping Beauty and Cinderella, to name just a few.
Robert Sheckley novelized Condorman, loosely based on his novel The Game of X.
Some Ellery Queen film adaptations received novelizations.
The dramatic novel by Peter George Red Alert was adapted to the Kubrik film Dr. Strangelove with a lot of satirical elements. George would go onto make a novelization of the film.
David Morell wrote First Blood, which was adapted into the Rambo series of films. Morell then penned novelizations of the first two sequels, which have more in common with the films than the original book since Rambo dies at the end of the original story.
Monk recieved a series of non-canon tie-in novels set throughout the series. Two of the plots from these novels (Mr. Monk Goes to the Firehouse and Mr. Monk and the Blue Flu) were later loosely adapted into episodes of the main television series (Mr. Monk Can't See a Thing and Mr. Monk and the Badge, respectively), albeit with some differences (The most significant being the main plot point of Can't See a Thing).
Full-scale adaptations are "Human Nature"/"The Family of Blood" (a Tenth Doctor TV story based on the Doctor Who New Adventures novel Human Nature), "Blink" (a Tenth Doctor TV story based on the prose Ninth Doctor annual short story "What I Did on my Summer Holidays, by Sally Sparrow") and "The Lodger" (an Eleventh Doctor TV story based on a Tenth Doctor Doctor Who Magazine comic story of the same title).
Looser adaptations are "Dalek" (a Ninth Doctor TV story loosely based on the Sixth Doctor Big Finish Doctor Who drama Jubilee, earlier drafts of which were reportedly much more heavily based on the audio), and "The Shakespeare Code" (a Tenth Doctor TV story loosely based on the Ninth Doctor Doctor Who Magazine comic strip story "A Groatsworth Of Wit").
The Third Doctor was partially based on James Bond, who was allegedly partially based on Jon Pertwee.
Red Dwarf's novel "Infinity Welcomes Careful Drivers" had some plots used for episodes of the TV show, notably in "White Hole". The book also explains a lot of what happened before most of the crew were killed, and some of it was adapted into Series 8. The book is often inconsistent with the show's plot, but this was done deliberately (it is inconsistent in show too). The other books "Better Than Life", "Backwards" and "Last Human" had some features put into the show too, but none as much as the first book.
The role-playing game phenomenon inspired the Niven & Barnes novel Dream Park and its sequels. R. Talsorian Games then adapted the novel into an actual tabletop RPG.
Magic: The Gathering sells a few of the decks used in its Duels of the Planeswalkers video game as pre-made decks. Of course, there's nothing but money preventing the dedicated player from making the decks himself.
Words With Friends: The Boardgame. Zynga copies the concept of Scrabble to make a video game, then licenses it back to Hasbro, the company they copied it from.
Street Fighter II inspired a Live-Action Adaptation simply titled Street Fighter, which in turn inspire not one, but two fighting games based on it, both titled Street Fighter: The Movie. The arcade version was made by Incredible Technologies. The console version, often mistaken to be a port of the arcade version, plays more like a standard Street Fighter game (specifically like a slower Super SF II Turbo) and it's generally considered a decent game, albeit not at the same level as the other games in the series.
Street Fighter II: The Animated Movie also had its own game version, albeit one that came out only in Japan. Instead of being a traditional fighting games, it was some weird pseudo-life sim where you controlled the newest model of Shadaloo's Monitor Cyborgs and develop his fighting abilities by watching FMV footage of the actual movie (along with new scenes made for the game) and "analyzing" the characters' special moves. There is a Super Turbo-style fight sequence in the end, but the Cyborg's moves are the same ones that Ken has in Super Turbo (including his Shoryu Reppa).
video game → collectible card game → video game. (And the promotional cards that came with the game and its strategy guide are based on those from the video game, adding another layer...)
Also, Yellow Version is video game → anime → video game. This eventually went double-recursive when Ash and Gary finally battled each other in the anime: Ash uses Pikachu while Gary uses an Eevee, which are the Pokémon their game counterparts start with in the Yellow Version.
It gets better. The Surfing Pikachu card is a reference to Pokemon Yellow, and is included in the video game version. That's video game → anime → video game → trading card game → video game.
Pokemon Puzzle League, aside from being an updated version of Panel de Pon, is a pretty massive recursive adaptation in its own right, given that the Puzzle Master is none other than Mewtwo from the movie. So the adaptation goes: game —> anime —> movie —> game.
Double Dragon inspired an animated series produced by DiC and Bohbot Entertainment, which had an American-developed fighting game tie-in titled Double Dragon V: The Shadow Falls. The Movie also had its own fighting game version for the Neo-Geo, which was developed by Technos themselves.
Hoo boy, Super Robot Wars. Initially a series of games centered around anime crossovers which eventually got a sub-series of games based on its Original Generation. Said subseries got its own Animated Adaptation and an OVA sequel. And then the first two OG games got a remake that changed plot elements to accomodate scenes from the anime, and a bonus segment based on the OVA. And after that, a Gaiden Game was released that continued the plot of the bonus segment and threw in elements from what was essentially a radio play. Together with all the Canon Immigrants getting tossed around between series and mediums, Super Robot Wars has more loops than your average roller coaster ride.
If you want to stretch it that far, Sonic Spinball is a video game loosely based on (read: has cameos from) the Sonic the Hedgehog, Sonic SatAM, and Archie Comics series (which were, as above, based on the original games), which eventually got its own comic adaptation.
There was going to be a straight example of this—that is, a Sonic game based on the SatAM cartoon, which in turn was based on the video games—but it was canceled.
Sonic Boom is a reimagining of the Sonic universe as an animated CGI cartoon series and will have a companion video game that acts as a prologue to the story of the cartoon.
Tomb Raider has an interesting example, in that it started as a game, and then became a movie which was a failure for fans of the game. And then the games became failure for fans of the game. Eventually, they borrowed elements from the movie to make the new game series (also putting a "Lara Croft" before the title, similar to the movies), which has actually made it more successful and relevant than its been in years.
F-Zero: GP Legend—a video game based on the anime of the same name, based upon the F-Zero franchise of video games.
Pac-Man → the Saturday morning cartoon Pac-Man → Pac-Land, a sidescrolling platformer based on the cartoon.
In Japan however, it became a (slightly) Dolled-Up Installment. It was still Pac-Land, but with changes made to certain sprites, including Pac-Man himself, where he looks more like Namco's official artwork.
The 2006 installment of Midway's Spy Hunter series was actually based on the movie that was based on the game series. Except the Spy Hunter movie upon which the game was based never ended up being released. Apparently they got tired of waiting, and decided to just release the game with no context.
Another Rhythm Game non-pure example; Pac Man and other old arcade games → Pac Man Fever by Buckner and Garcia → Pac Man Fever on Rock Band, including a song about Donkey Kong available on Xbox 360 and PS3.
Roadside Picnic (novel) → Stalker (short storynote expanded into a script, by the same people plus Tarkovsky) → Stalker (Tarkovsky movie) → S.T.A.L.K.E.R. (video game) → numerous novelizations → movie based on one of them.
The additional cars and tracks from the home versions of San Francisco Rush 2049 were incorporated into the Updated Re-release /Special Edition of the arcade version, as well as two of the BGM's from the Dreamcast version to go with the new tracks. The tracks also had new shortcuts added.
Transformers started out as toys, went to an animated series, which then introduced new toys, some of which were used for new Transformers series, or for The Movie, which got its own line of toys.
Another Hasbro franchise to which something similar happened is My Little Pony. It started out as a line of plastic toy ponies with accessories, and in order to boost sales, an animated series was produced. Three generations later, since My Little Pony: Friendship Is Magic was launched, the toys are more and more based on the animated series which in turn is based part on the first generation toys (or how Lauren Faust characterized them), part on the third generation (In Name Only, though).
The theatrical version of Disney's The Hunchback of Notre Dame. The theatrical version was notably Darker and Edgier than the Lighter and Softer Disney adaptation, keeping the dark tone of the book (having Esmeralda and Quasi die at the end, Frollo being a (former) priest, etc.) whilst keeping the plot points from the Disney version (Clopin being a sort of narrator, Frollo being a bastard, the lack of Gringorie, etc.)
Japanese pro soccer player Hidetoshi Nakata cites the Captain Tsubasa manga and anime as his inspiration for pursuing a career in soccer. He got a cameo in Inazuma Eleven 2 via a secret character based on and named after him. Said character became an Ascended Extra in the third game and consequently also appeared in the corresponding arc of the anime adaptation. In short, anime → real life → game → anime.
Cabaret: Real Life → book (Berlin Stories) → fictional play (I Am A Camera) → Musical → Movie (Which has a closer plot to the play, but uses songs from the musical.)
Adrian Mole started out in 1982 as a BBC radio play called The Diary of Nigel Mole. The Adrian Mole books were then adapted for Radio 4, with the same voice actor, Nicholas Barnes. In 1985 Sue Townsend wrote some original Adrian Mole material for Radio 4's summer holiday programming (again with Barnes), wich later became "Adrian Mole at The BBC" in her True Confessions of Adrian Albert Mole book. So radio → book → radio → radio → book. Further books have come out at random intervals every few years since, featuring Adrian's diaries from the age of 13 3/4 to over 40.
Baby's Tears started out as a Konami original song in Dance Dance Revolution SuperNOVA. It got drastically remixed (different instrumentals, different lyrics, slower tempo; about the only thing that stayed the same was the melody) into an Anime Theme Song as the opening theme for the Sky Girls OVA. The anime version subsequently appeared alongside the original in DDR SuperNOVA 2, listed as "Baby's Tears (Sky Girls Opening Theme)".
Taco Bell's Doritos Locos Tacos are being adapted into Doritos Locos Tacos flavored chips. It's a mix of either nacho cheese or cool ranch and "taco flavor" chips. The world quietly weeps, but also get ready to go grocery shopping.
Radicalfaith360 is a YouTube user known for his re-enactments of YouTube Poop. Since becoming popular, his re-enactments have become sources for poops on their own — often by the very same users who made the poops he was re-enacting in the first place.
The Heckler & Koch G3 rifle: Unproduced Nazi German gun (StG-45) → Spanish gun based on its plans (CETME Modelo B) → licensed German copy.
Girl Genius Radio Theatre strips: Webcomic → live performances and podcasts → webcomic.
Thomas the Tank Engine garnered its own promotional magazine series, with some of its original stories actually adapted into episodes of the show itself in Seasons Three and Five. Incidentally the magazine's writer at the time eventually ended up lead writer for the show come Season Seventeen.