David Duchovny was one of the many actors who was tested for Batman after Michael Keaton left the role. Duchovny later said his nose looked enormous in the cowl. Duchovny also tested for the role of Bruce Banner when a replacement for Eric Bana was being sought.
I remember reading the story about Duchoivny in the 1990s, but I've since seen an interview with him where he's said that it was untrue.
After the B&R debacle, when WB had no idea how to proceed with the franchise, I remember reading that there was to be a Batman v Superman movie, with the then-incumbent George Clooney playing opposite John Travolta (?!) as the Man of Lard, sorry, Steel. Then Richard Donner was supposed to be directing Mel Gibson (Bats) opposite Daniel Day-Lewis (Supes).
This project never seemed to go beyond wishful thinking but several years later Wolfgang Peterson was linked to another BvS project. While most young Hollywood actors seemed to be up for both roles, it was at one stage stated that Colin Farrell would be Batman and Jude Law Superman (Law had also been linked to the JJ Abrams abortive project).
As you all know, this never happened, with Peterson going on to make Troy instead. However, a few years later, the German director reckoned that he'd still like to make it. However, he didn't want to use Bale and Routh, he wanted to cast his Troy stars Eric Bana and Orlando Bloom in the lead roles.
This was a bit like the equally-abortive Worlds Finest project, which also would have eschewed Bale & Routh in favour of new actors in the roles. IIRC, some tv actor called Arne Hammer was supposed to have landed the role of Batman, Jessica Biel turned down Wonder Woman because she would not then have got to play the role in a solo WW movie, while Teresa Palmer was then supposed to play the role. Can't remember if they cast a Superman, before they came to their senses.