Classics Illustrated #26 - Frankenstein (1945)
I bought this rare 1945 edition of Frankenstein (Classics Illustrated #26) at a used bookstore in Hawaii when I was a mere sprout, and it stayed in remarkably good condition considering that nobody took any special efforts to preserve it. The interior pages are also in great shape.
UPDATE at 3/27/10 6:52:01 pm:
Comic book aficionado ‘ckb’ has informed me that this book actually dates from the late 60s, not 1945 as I originally believed; I was fooled by the 1945 copyright mark on the first page. Still rare but not as rare as the 10-cent 1945 edition.