I still think when it comes to superhero comics being so practically inaccessible (with comic shops being hard to come by, said shop might not have enough stock of those comics and even those readers have other things to do), that it seems almost any other non-comics adaptation eclipse them by being more accessible to the masses. They even influence the comics in return.
To put it this way, if Caitlin Snow becomes a werewolf on the Flash programme she will become a werewolf in the comics as well. Same with making Stephanie Brown into a bitter Red Lantern after witnessing Tim kill her pets. It’s going to shape people’s preconceptions and perceptions of the character way more than comics do.
Likewise with the Joker, it’s parsimonious to say that the most influential Joker actor in recent memory is Heath Ledger that it practically spawned memes. (Joaquin Phoenix’s take’s increasingly influential in its own right however with protesters dressing up as him.) Better yet Felicity Smoak.
Originally in the comics, she was somebody’s irritable dark-haired mother. However on telly she was reinvented into somebody else that it influences subsequent comics portrayals of her. If comics are so hard to come by that television and cinema become the major points of reference for character portrayals.