I also love The Creeper as created by Steve Ditko, in SHOWCASE 73, and his own series BEWARE THE CREEPER 1-6. And also by Neal Adams in BRAVE & THE BOLD 80, and O'Neil/Novick/Giordano in DETECTIVE 418, DETECTIVE 444-448, THE JOKER 3, and Dematteis/Maguire in JUSTICE LEAGUE 6 and 7, among other appearances.

I'm at a loss to explain exactly why the character resonates for me, but he does. And apparently does for many other fans as well.

Some other favorites for me are Zatanna, the Royal Flush Gang and Queen Bee (both villains from early Fox/Sekowsky JLA issues), Kirby's THE DEMON, Swamp Thing, Phantom Stranger, and O.M.A.C.