X-Men (Vol 1 1963) Issues 1-50
The first 50 issues of the X-Men kicked off with co-creators writer Stan Lee and artist Jack Kirby until issue #20 when Roy Thomas took over the writing and Werner Roth, Dan Adkins, Ross Andru, Don Heck & others contributed to the art/design. Key issues include;
#1 - 1st appearances Professor Charles Xavier, Magneto, Cyclops, Beast, Angel, Iceman, Marvel Girl
#2 - 1st appearance The Vanisher #3 - 1st appearance The Blob
#4 - 1st appearance of Mastermind, Toad, Quicksilver, Scarlet Witch.
#8 - 1st appearance of Unus #9 - 1st appearnace of Lucifer
#10 - 1st appearance of Ka-Zar, Zabu #12 - 1st appearance & Origin of Juggernaut
#16 - 1st full appearance of Master Mold #19 - 1st appearance of Mimic
#28 - 1st appearance of Banshee #35 - 1st appearance of Changeling
#44 - First Silver Age appearance of Golden Age Red Raven
#49 - 1st appearance of Polaris