16-years on, George Clooney still regrets his role as Batman. In an interview with Deadline, Clooney revealed that he kept a photo of himself as Batman "prominently displayed on his office wall, as a cautionary reminder of what can happen when you make movies solely for commercial reasons."

When he signed onto "Batman & Robin", Clooney was still revered as the original McSteamy on the NBC drama "E/R". But he thought the role as Batman would be his big break.

"My phone rang, and the head of Warner Bros said, 'Come into my office, you are going to play Batman in a Batman film' and I said, 'Yeah!' I called my friends and they screamed and I screamed and we couldn’t believe it!" Clooney told Total Film Magazine.

"I just thought the last one had been successful so I thought I was just going to be in a big successful franchise movie."

Unfortunately, the movie flopped when it hit theaters in 1997, earning a domestic lifetime gross of $107 million on a production budget of $125 million. It nearly ruined the entire franchise, before Christopher Nolan saved it with "Batman Begins" in 2005.

"With hindsight it’s easy to look back at this and go, 'Woah, that was really s--- and I was really bad in it,'" Clooney said. "It was a difficult film to be good in."

He soon realized that he needed to steer away from flashy movies that are "wastes of money."

"At that point I realized I'd better start picking better. My next three movies were 'Out Of Sight,' 'Three Kings and O Brother,' 'Where Art Thou?'" Clooney said, according to Digital Spy. "It was, 'OK, at last I understand now what I want to do.'"

Now his latest film "The Monuments Men" is set to hit theaters December 2013. It's an untold story of World War II starring Matt Damon, Cate Blanchett, Bill Murray, John Goodman, and George Clooney himself who wrote and directed it.

Check out the trailer below: