DC's first continuity ran from 1935-roughly 1955. This was a very creative time in comics, probably the most creative, if not sometimes formulaic. This was the time when the concept of Super Heroes was born- as well as teams. The Justice Society of America is my all time favorite team in comics, and date from this time period. The Golden Age transition to the Silver Age was not a hard transition, but for my purposes, I am going with Showcase #4 as the demarcation line, although I know it's really academic as those comics will always be out of my price range. In fact, I'm not sure I even have any Golden Age books in my collection; I am creating the album now (8/2/2015) mainly so I can write up the caption. I don't think I have any Golden Age books from DC of my own, although it's been more than a decade since I have seen my collection, so my memory may not be correct.
Growing up I had access to an extensive collection of DC Comics that dated from 1940-whatever year it currently was, but I don't anymore, and, as they were not my comics to begin with, would not be put into the album anyway.
For Christmas 2015 I received my first 5 Golden Age Captain Marvel books. (Through reprints, the Golden Age Marvel Family became my all-time favorite super heroes) While these were published by Fawcett, not DC, I am including them here at this time...I may end up breaking out the Fawcett family of books to their own album some day.