I think the best annual of all time was AMAZING SPIDER-MAN ANNUAL 1, Sept 1964, by Stan Lee and Steve Ditko. With cameo appearances of just about every hero in the Marvel universe with his own title at that time crossing paths with Spider-man.
And the "Sinister Six", six of Spiderman's villains taking him on in a single story. With a poster-worthy splash panel of Spider-man fighting each of them (the Vulture, Kraven the Hunter, Mysterio, Electro, Sandman, and Doctor Octopus).
I first purchased this story reprinted in SPIDERMAN ANNUAL 6 (1969), which was actually even better in this reprint version, because it included "The Fantastic Four Meet Spiderman" (from FANTASTIC FOUR ANNUAL 1, 1963, by Lee/Kirby/Ditko), and Spiderman Tackles the Torch" (from AMAZING SPIDERMAN 8, Jan 1964, also Lee/Kirby/Ditko)
This book was among the first Marvel comics I read, and a fantastically fun introduction to the Marvel Universe.
I now have it also with nicer printing in the first two volumes of Marvel Masterworks collected reprints of the Lee/Ditko SPIDER-MAN run. But somehow it's more fun for me to read it in its original ANNUAL 6 form.
