Originally Posted by
Revolutionary_Jack
I kind of think that almost everything in the 60s was important. But anyway:
1) AF#15 -- Spider-Man's origin story which was so good that it led to the launch of an ongoing months after its publication and the cancellation of Amazing Fantasy.
2) ASM #1 -- J. Jonah Jameson's first appearance.
3) ASM Annual #1 -- First appearance of the Sinister Six, which also provided a showcase of Spider-Man's rogues gallery -- Dr. Octopus, Mysterio, Kraven the Hunter, Vulture, Electro, the Sandman).
4) ASM #31-33 -- "If this be my destiny/Master Planner" which introduced major parts of Peter's supporting cast. Images and bits of this story remain relevant and constantly referenced and alluded to.
5) ASM #5 -- This is the issue where Spider-Man fights Doctor Doom. It's important because Doom is the first Marvel-wide rogue Spider-Man fights, and likewise, Spider-Man is the first non-FF hero Doom fights. This issue cemented Spider-Man and Doom as respectively major Marvel-Wide characters, with Doom's dynamic with Spidey proving his versatility to menace virtually any hero Marvel can create from now onwards, while Spider-Man's tussle with Doom sets the stage for later encounters with Juggernaut and Firelord to name a few.
6) ASM #39-40 -- This two-part issue is the first Post-Ditko one and the first with Romita Sr. It was a test as to whether Spider-Man could continue without the art (and more than that) of co-creator Ditko. It also had to resolve the Green Goblin mystery set up from before in a way that provided a decent payoff while also confirming Green Goblin's threat and menace level. Somehow it succeeded and this issue was a major success and iconic elements that endure to this day. Also the first ASM comic that both DeMatteis and Roger Stern read.
7) ASM #42-43 -- The first on-panel appearance of Mary Jane Watson. As with Goblin, Romita Sr. had to provide a payoff to a Ditko-era subplot that lived up to the long build-up (MJ was first mentioned in ASM#15, so 27 issues in the making). Romita Sr. not only succeeded but exceeded expectations and provided an iconic and charismatic character introduction, as well as introduced the most important character in the stories after Peter Parker in the process. Also first appearance of Rhino, Romita Sr's first major new villain and an enduring Post-Ditko Rogue (that some actually think was made by him since it so clearly fits the theme and design principles of his rogues). MJ's characterization here, someone who likes both Peter and Spider-Man, who accommodates both roles, as when she helps Peter go the fight with Rhino also highlights the role she would eventually occupy.
8) ASM #50-52 -- "Spider-Man No More", iconic splash image, cover, and recurring theme and motif. As well as first appearance of Kingpin, and more importantly first appearance of Joseph "Robbie" Robertson, a major supporting character and the first and longest-lasting and most important African-American supporting character in Spider-Man, an attempt by Lee, now that the Civil Rights was slowly becoming mainstream, to introduce diversity to what had been an all-white ensemble at the outset. Also featured the death of Frederick Foswell, major Ditko-era supporting character, which proved that violence would never be far in Spider-Man.
9) ASM #47 -- This comic was a major touchstone in Spider-Man Blue and Spider-Man Life Story #1. The opening has a flashback retcon that reveals that Green Goblin had dealings with Kraven before his amnesia, which leads Kraven to attack Norman post-amnesia in the present. This is essentially the first Untold Tales of Spider-Man, with Stan Lee introducing a new story in a status-quo that had been broken in present but done so in a way that didn't contradict what had been established. The comic also had Flash Thompson going to Vietnam, with Peter wishing him goodbye. It also codified the Peter-MJ-Gwen romantic triangle, with the famous dance scene (reproduced in Blue, To have and to Hold).
10) ASM #28 -- This issue featured the most lasting status-quo change of Peter graduating high school and going to college, going from teenager to young adult. After this one had to wait until ASM Annual #21, and unfortunately after OMD, one is yet again in a position of waiting.