And likewise us saying that we prefer such and such in The Batman doesn't mean that we don't like or love any number of similar elements in prior films. We've now had what six live-action Selina Kyles (going back to 1966) and I like them all, even if I put Kravitz at the top. And before somebody mentions Halle Berry keep in mind I said Selina Kyle not Catwoman, lol.
Heath Ledger's performance was brilliant but as a character I thought he suffered from a lame master plan with the ferries and the killing of Michael Jai White off camera with no residual blood or even an appropriate accompanying sound effect was just dumb. TB's Riddler might not have reached the singular height of the TDK interrogation scene but he had an awesome master plan (and the most competent one since Arnold froze Gotham, lol) and his personal kills were handled much better IMO. Those are a couple reasons I found him to be a more consistently solid character.
Obviously if you want to distill the two characters to just cultural impact, iconography, or appearance or what have you I can easily see someone putting Ledger Joker far above TB Riddler. But based on my criteria I prefer the latter.