My love of DC's Golden Age characters came from Super Adventure Comics #61. This reprinted a few stories, but the one that really stood out for me was "The Unknown Soldier of Victory", the JLA/JSA/Seven Soldiers team-up from JLA 100. I loved the JSA and couldn't get enough of those JLA/JSA crossovers.
My very first included an Earth-2 story too and I completely fell in love with that idea. I was in for JLA/JSA from day one.