I'm pretty sure The Marvel No-Prize Book (1982) is unique in the history of comics: a one-shot devoted entirely to chronicling a company's mistakes over the years. With Stan Lee as narrator, the comic points out all sorts of goofs: characters given the wrong name (Spider-Man's secret identity is "Peter Palmer" in Amazing Spider-Man # 1), stories with poor continuity (Captain America's shield destroyed in one panel, and back on his arm the next), and art goofs (my two favorites being a one-eyed pirate looking through a periscope with an eye-patch, and Daredevil inexplicably depicted with a pistol and holster). The best one comes from Tales of Suspense # 92, as Captain America threatens an enemy:
"Okay, mister--I'm ready for you! So let's wrap it up! Only one of us is gonna walk out of here under his own steam--and it won't be me!"