Actually, as I think of it, a book I was given as a Christmas gift in the early 1970's, BATMAN FROM THE 30's TO THE 70's, clinched it for me, giving me 4 decades of reprints in one volume.
In particular the 70's section, all from 1970-1971:
DETECTIVE 395 "The Secret of the Waiting Graves" by O'Neil/Adams/Giordano,
BATMAN 217 (Robin graduates high school) Robbins/Novick/Giordano,
DETECTIVE 402, "Man-Bat", Robbins/Adams/Giordano,
BATMAN 227 "The Demon of Gothos Mansion", O'Neil/Novick Giordano.
These classics from 1970-1971 let me know there was a run of great stories that just preceded the beginning of my Batman reading, and sparked a burning hunger in me for mail-order back issues. Most of these were only a buck or two at most when I began reading.
I was crushed when O'Neil and Novick/Giordano left BATMAN in 1975.
And it wasn't until 1979 when I first read the Englehart/Rogers DETECTIVE issues, and saw another comparable run to O'Neil's.
