Amazing Spider-Man #100, released in September 1971, is a landmark issue for the series. Here's a breakdown of the issue:

Significance:

100th anniversary issue (though technically it wasn't the 100th issue published)

Features a classic cover by John Romita Sr. depicting a dramatic inner struggle between Peter Parker and Spider-Man.

Considered a key issue for collectors.

Story:

Titled "The Spider or the Man?" and written by Stan Lee with art by Gil Kane.

Peter Parker wrestles with his dual identity and the challenges it brings to his personal life, particularly his relationship with Gwen Stacy.

The story features cameos by some of Spider-Man's most notable villains, including the Green Goblin, Doctor Octopus, and the Lizard.