The group of 100-pagers I consider to have the best selection of reprint material is
DETECTIVE COMICS 438-443.
Ranging from golden age Simon and Kirby Manhunter and Newsboy Legion, to Golden Age Bob Kane Batman, to Quality Comics material like Gustavson's The Spider. Along with early 1940's stories of Dr Fate by Howard Sherman, of Spectre by Bernard Baily, Eclipso by Toth, and 1940's Hawkman and Green Lantern stories by Kubert and Infantino when they were still in their teens but working professionally! And what a contrast with their more recent 1960's work. To Showcase 73 featuring Ditko's first Creeper story(that introduced me to the character), to early 60's Kubert Hawkman stories, Gil Kane silver age Atom stories, and Batman reprints that span the whole era from the 1940's to the 1960's.
DETECTIVE 444 and 445 are also 100-pagers, but these last two had stories selected by returning editor Julius Schwartz, that were late 1950's/early 1960's heavy. As I recall, E. Nelson Bridwell selected stories that went into 438-443.
Also noteworthy are the exceptional pulpish-looking covers:
438 by Kaluta
439 by Neal Adams.
440-443 covers by Aparo.
Also noteworthy in these issues are the exceptional new material, particularly the 7-part award-winning Goodwin/Simonson "Manhunter" series, and the great Batman lead stories, mostly written by Goodwin as well, in 438 (art by Aparo), 439 (the award-winning "Night of the Stalker", art by Almendola/Giordano), 440 (art by Almendola/Giordano), 441 (art by a very new to the field Howard Chaykin), 442 (art by Alex Toth), 443 (the 20-page Manhunter grand finale by Goodwin/Simonson)
Memorable all the more for a nice mix of great new material, in combination with a great selection of golden/silver age material.
