Spiderman finds burglar that killed uncle Ben
The most important event in Spiderman is when he apprehends the man who is responsible for the death of his uncle but whom he did not capture the first time he could. Somewhere before this incident, Spiderman had he chance to go after the man but chose not to because he did not feel responsible. This occurs in the first half of the first issue, and has influenced all of his actions afterward.By not taking action the first time, he feels indirectly responsible for his uncle's murder. This classic moment from a classic story is Spider-Man's defining moment, and the moment that taught him that with great power comes great responsibility. As a reader, you are very sympathetic to his plight and this plot twist really keeps you on you toes for the rest of the issue.