These were the comics dated May 1963. (I realize they would have been on the newsstand maybe two months earlier, but let's not nitpick.)
A-B:
Action Comics 300
Adventure Comics 308
Adventures Into the Unknown 140
The Atom 6
Baby Huey in Duckland 3
Baby Huey and Papa 7
Barbie and Ken 3
Batman 155
Battlefield Action 47
Betty and Veronica 89
Blackhawk 184
The Brave and the Bold 47
Replies
C-F:
Car 54 #5
Casper the Friendly Ghost 57
Cave Kids 2
Challengers of the Unknown 31
Dennis the Menace 66
Detective Comics 315
Devil Kids 6
Falling in Love 59
Fantastic Four 14
Fightin' Air Force 38
Fightin' Army 52
The Flash 136
Forbidden Worlds 111
The Fox and the Crow 79
Frankenstein
The Frogmen 5
G-J:
G.I. Combat 99
Girls' Love 95
Gunsmoke Western 76
Harvey Hits 68
Heart Throbs 83
Hot Rods and Racing Cars 63
Hot Stuff Sizzlers 12
House of Mystery 134
Hunk 11
The Jaguar 12
Journey Into Mystery 92
Jughead 92
Justice League of America 19
K-L:
Kid Colt, Outlaw 110
Kid Montana 40
Konga 12
Laugh 146
Life With Archie 20
Little Audrey and Melvin 7
Little Dot Dotland 6
Little Dot's Uncle$ and Aunt$ 6
Little Lotta 47
Superman's Girlfriend Lois Lane 41
Love Diary 27
Love Romances 105
M-O:
Magnus,Robot Fighter 2
McHale's Navy 1
Metal Men 1
Mickey Mouse 87
Millie the Model 114
Mutt and Jeff 135
My Greatest Adventure 79
My Little Margie 47
Mystery in Space 83
New Terrytunes 3
Our Army At War 130
Our Fighting Forces 76
P-R:
Peanuts 1
Pep 162
The Phantom 3
Private Secretary 2
Richie Rich 17
The Rifleman 15
S:
Sad Sack 141
Sad Sack's Funny Friends 45
Six-Gun Heroes 74
Snooper and Blabber 3
Space Adventures 51
Space Mouth 3
Space War 22
The Amazing Spider-Man 2
Star Spangled War Stories 108
Strange Adventures 152
Strange Tales 108
Submarine Attack 39
Sue and Sally Smith Flying Nurses 51
Sugar and Spike 46
Supercar 3
Superman 161
T:
Tales of Suspense 41
Tales of the Unexpected 76
Tales to Astonish 43
Tarzan 135
Texas Rangers in Action 39
Three Nurses 18
Tom and Jerry 215
Treasure Chest Vol. 18 No. 18
Ttreasure Chest Vol. 18 No. 19
Tuff Ghosts 6
The Twilight Zone 3
Two-Gun Kid 63
U-Z:
Uncle $crooge 42
Unknown Worlds 23
Unusual Tales 39
U.S. Airforce 27
Walt Disney's Comics and Stories 272
Wonder Woman 138
World's Finest 133
The Young Doctors 3
I was around for this. I know I bought the ATOM, FANTASTIC FOUR, FLASH, and JUSTICE LEAGUE issues depicted when they first were on the racks. Many of the others I had bought previously or started buying soon after this. It's striking how much variety there was back then. I used to greatly enjoy the ACG ghost comics (FORBIDDEN WORLDS, etc.) and Schwartz science fiction books. I started MAGNUS ROBOT FIGHTER a few issues after this, SPIDER-MAN and the other Marvel books shortly thereafter. The Marvel westerns were fun and may have been my first exposure to Jack Kirby. I came to appreciate the Charlton war books much later, mostly for their relative realism vs Sergeants Rock and Fury.
Richard, it's interesting when you look through them all and you can see Marvel was really a fledgling company (despite Timely and Atlas) in May 1963. That particular month, they had 11 comics come out, and only 6 of them had super heroes. DC was clearly the leading company at the time.
May 1963 cover dated comics were among the first ones I remember reading. Since they would have come out around February, I wonder if my Dad gave me money for my birthday in that month or said I could purchase some of the comic books. I recognize a number of the DC titles as being on the spinner racks atthe time, but, oddly enough, not the Marvels. I have looked at some of the release dates for Marvels for 1963 and I got interested in them, too, but not until a few months after the other companies.