the Kree-Skrull War

The Kree-Skrull War is considered a milestone in Marvel Comics, one of the first huge multi-parts stories in comic book history. I think the first was Mr. Mind and the Monster Society of Evil in "Captain Marvel"

it's full of great art and some really cool storylines, but the main crux of the story is based on a mistake.  Roy Thomas and Neal Adams based the invasion on the final panel of Fantastic Four #2, with three hypnotized Skrulls living life peacefully as cows (they hated being Skrulls).  according to Thomas and Adams, there should have been four.

however, on page 23, panel five, Reed Richards states "The fourth is on his way to another galaxy now with the rest of his invasion fleet!"

so Stan and Jack knew what they were doing by having only three cows.

anyway, re-reading it now I think the story is a little cumbersome, though there are a lot of great elements to it, especially the fantastic voyage inside the Vision, which laid the groundwork for a whole mess of stuff later on.  and by now, it's a huge mess.