Key issues
X-Men Comic Books: The Key Issues and What Grade Does to Them
The first X-Men comic is The X-Men #1, cover-dated September 1963, from Marvel Comics by Stan Lee and Jack Kirby. The books collectors chase most are that issue, Giant-Size X-Men #1 (1975), X-Men #94, #101 and #129, and on all of them the CGC or CBCS grade is the largest driver of price.
Updated Oct 11, 2026