Which Batman graphic novels are considered standalone stories that don't require following a strict continuity or reading order?

Many classic Batman graphic novels can be read as standalone stories without needing a strict continuity order. Examples include "The Dark Knight Returns" (an alternate future masterpiece), "Gotham by Gaslight" (an Elseworlds story set in Victorian times), "Batman: White Knight" (an acclaimed alternate universe series), "Batman: Ego," and various "Black Label" titles like "Batman: Damned." These stories are self-contained and offer unique takes on the character and his world.