Wolverine: Origins exists to "fully" detail Wolverine's mysterious past, has also been called continuity porn. Note that all of the hinted-at elements of Wolverine's past have already been revealed; Origins deals with this by making up an entirely new Ancient Conspiracy and trying to work it in around the edges. At this point, anything dealing with Wolverine's Expansion Pack Past is probably continuity porn by default.
Lampshade Hanging/parody in an issue of She-Hulk, which promised to fix almost all of Marvel's past and future continuity problems. And did, sort of: any appearances by a character you don't like are actually a tourist from another universe cosplaying as that character.
Not to mention that the entire Dan Slott run of She-Hulk abounded with often obscure jokes about Marvel continuity — to the point where they had the law firm with a COMIC BOOK COLLECTION and She-Hulk reads the first issue of... well, her.
Chris Claremont's quasi-trilogy X-Men: The End pulled together tons of old storylines he either left hanging or were quashed by editors / other writers, along with a number of others, into a semi-Bad Future story that tried to reconcile the tangle that the X-Books had become.
The infamous Continuity Xorn escapades. Just who was Xorn really, and what were his actual motivations? Three different writers gave three different takes in order to clean it up but each just got more and more convoluted and complicated until really the best thing to do was just throw it all into the sun.
Kurt Busiek is fond of continuity, and has proven quite capable of weaving disparate continuity threads into a cohesive (and entertaining) whole.
Avengers Forever is probably Busiek's most Continuity Pornastic piece of writing. Among other things, it explains how almost every major event in the history of the Avengers — and the histories of the Avengers in every parallel universe — was either caused by Immortus or cleaned up by him afterwards to save the human race from the Time Keepers. It also spent an entire issue detailing the history of sometime Big Bad Kang the Conqueror. However, because time travel is an important part of the series, and because the story is generally good, it usually manages to get away with it.
His The Avengers run as a whole also counts. In addition to featuring many characters from across the franchise's history, he also set out to resolve some old dangling plot threads and Aborted Arcs from previous writers, such as finally clearing up what the hell was up with Madame Masque.
An earlier example of Kurt Busiek was Marvels, a four-issue mini-series that managed to encapsulate the entire early history of Marvel Comics (from World War II to the Death of Gwen Stacy) and present it from a street-level point of view, showing how an average man sees the Marvel Universe.
The related Marvels Project did the same with a greater focus on the WWII superheroes. It stars the Golden Age Angel, who is retconned to have been inspired to become a hero by Matt Hawk, the Two-Gun Kid (the most famous Marvel Western hero and time-traveling Avenger), and includes pretty much every superhero from that period, including ones that had yet to reappear in the pages of other books.
Christopher Priest's Black Panther run was basically a celebration of the character's entire published history up to that point, with Priest making sure to incorporate something from pretty much every previous take on the character, even the stuff that wasn't well regarded (such as Jack Kirby's run). Priest has said that in hindsight, this was probably part of the reason why it didn't sell very well despite being critically acclaimed.
Marvel pulled one of these with Secret Invasion. Character derailment, you say? Alien mole!Too many of one guy to make sense in universe? Alien double! Character death of your favorite minor character, even though it was a powerful move and strongly affected the rest of the characters? Alien doppelganger!
Spider-Man' Brand New Day, Maximum Clonage, and a lot of JMS's writing went into heavy continuity nods and switches. And usually by the end a lot was left hanging.
And still left hanging. One More Day/Brand New Day seems to be going out of their way to avoid continuity porn and ignore the continuity problems that have been created because of the situation.
Eventually they wrote One Moment in Time, or OMIT, that explained exactly how continuity changed because of OMD. The Wedding Annual, MJ's pregnancy, and, ironically, One More Day itself are the only things in which anything beyond Spidey's marital status was changed.
Earth X and its two sequel series Universe X and Paradise X are intentional works of pure continuity porn. Set 20 Minutes into the Future (from the year 1999), the story explains, combines, and wraps up every continuity snarl, dangling plot-thread, and unexplained coincidence the writers could lay their hands on, including characters, dimensions, and devices no one's written about for decades. Fortunately, each series also features Interactive Narrator characters to keep the readers on top of what they absolutely need to know for the plot, but it's still very likely you'll to spend more time reading This Very Wiki or The Other Wiki than the books themselves.
Everything Al Ewing ever touched at Marvel, as he seems to be the living embodiment of the Marvel Wiki. Mighty Avengers? Referenced everything up to freaking Nextwave. Loki: Agent of Asgard? It literally caps all the continuity surrounding Loki, but not above referencing stuff as early as Walter Simonson or Avengers #1 from the silver age. etc. It's a testament to his talent that his series are generally perfectly readable without knowing this but be assured he doesn't forget continuity ever.
