The 1983 D&D "Red Box" Basic Set. It was love at first sight. Although TSR had many amazing artists including great ones like Jeff Easley, Brom, Clyde Caldwell, Stephen Fabian and others, there were few who to such a degree defined the D&D experience as Larry Elmore. I am happy that Dave Arneson's company chose this artist for the D20 version of Blackmoor.
Happy birthday Larry Elmore!