I loved the Nolan Batfilms and consider them to be the definitive versions of the character, as far as live action Batman films goes. (Batman: The Animated Series is the definitive version of Batman pretty much overall).
But I really would like to see some of the more fantastical Bat-villains show up in a new Batman film. The kind of baddies from the rogues' gallery who Nolan thought were too 'out there' for his films, like Clayface, Manbat and even the Penguin (who could have been done realistically even in a Nolan Batman film, IMO).
Having finally gotten the Batman films I've always wanted, thanks to Nolan, I'm now open to any new interpetation of the Dark Knight, just so long as they don't go overboard with the camp (such as in Batman Forever and Batman & Robin).