It’s easy to have Bat envy. He gets the car, the gadgets, the mansion — what’s not to love? “I dressed up as Batman at Halloween,” admits Aaron Eckhart (Harvey Dent/Two-Face). “I had the sheets and the pillows and everything. I was a fan.”

But if some of the “Dark Knight” cast had their druthers, they’d play someone else — just for kicks.

“It shows Christopher Nolan has imagination that he didn’t cast me as the villain,” said Gary Oldman (Jim Gordon), “since somehow I got into this thing of always playing these eccentric characters. But I always liked the Riddler. I liked the whole Riddle aspect. I loved the suit. I thought the suit was pretty cool. You have to be pretty fit, though, don’t you, to wear the Riddler outfit?”

Same for Catwoman’s outfit, but Maggie Gyllenhaal (Rachel Dawes) is willing to try it on for size. “I liked Michelle Pfeiffer as Catwoman,” Gyllenhaal said.

“There was alaways a Batman movie out in the summer when I was growing up, but I usually couldn’t care less. But doing this movie, I started to get it. I felt it. I understood.” Especially when she’d had a scene where “Batman would save me from certain death and envelope me with his cape,” she said. “I thought, ‘Oh, that kind of feels good.’ ”

And since Catwoman is sometimes saved by Batman, Gyllenhaal said she wouldn’t mind borrowing one of her nine lives, just to relive that experience. “Yeah!”