The ultimate fate of the Simon and Kirby 1970s version of The Sandman ended tragically, with him taking his own life due to loneliness of being semi-trapped in the Dream Dimension. Hector "Silver Scarab" Hall then became the next Sandman in another tragic turn of events.
If DC didn't fold all their versions of Sandman into the Vertigo line, I would have liked to think that Jed Walker/Paulsen would have been a good idea to be the successor, since he was a more-or-less prominent supporting character in the short-lived 1970s series.