Deciding which Silver Age comic books to buy depends on various factors, including personal preferences, budget, and investment goals. The Silver Age of comic books, roughly spanning from the late 1950s to the early 1970s, is known for introducing iconic characters, revitalizing the superhero genre, and featuring groundbreaking storylines and artwork. Here are some key Silver Age comics that are highly regarded by collectors and enthusiasts:

Amazing Fantasy #15: This issue, published in 1962, marks the first appearance of Spider-Man. It's one of the most sought-after and valuable comic books of the Silver Age.

Fantastic Four #1: Published in 1961, this issue is the debut of Marvel's Fantastic Four superhero team, created by Stan Lee and Jack Kirby. It's considered a cornerstone of the Marvel Universe.

The Incredible Hulk #1: Another iconic Marvel comic, this issue from 1962 introduces the Hulk, one of the most enduring characters in superhero fiction.

Detective Comics #359: This issue, published in 1967, features the first appearance of Barbara Gordon as Batgirl, a character who has become a staple of the Batman mythos.

X-Men #1: Published in 1963, this issue introduces the mutant superhero team known as the X-Men, created by Stan Lee and Jack Kirby.

The Amazing Spider-Man #1: Although not the first appearance of Spider-Man, this issue from 1963 marks the character's first solo series and is highly sought after by collectors.

Tales of Suspense #39: This issue, published in 1963, features the debut of Iron Man, one of Marvel's flagship characters.

Green Lantern #76: This landmark issue from 1970, written by Denny O'Neil and illustrated by Neal Adams, is considered the beginning of the "Bronze Age" of comics and features a socially relevant storyline.

When considering which Silver Age comic books to buy, it's essential to research each issue's historical significance, condition, and current market value. Additionally, investing in graded copies from reputable grading services can provide assurance of authenticity and condition, potentially increasing their long-term value.