IT'S A BRAD, BRAD, BRAD, BRAD WORLD - by Donna Freydkin

He's more than just a pretty face -- but it is a really cute face.

Brad Pitt is ranked 20th in Forbes' list of powerful celebrities and earns an estimated $20 million a movie.

But he increasingly has gained respect for being more than just a pretty face. To those in the business, his appeal is as obvious as those piercing baby blues.

'He is arguably one of the biggest stars in the world, if not the biggest. Men want to be him, and women want to be with him,' says Jerry Weintraub, who has produced the 'Ocean's' movie franchise and has been friends with Pitt for years.

Pitt's career has never been better. He's starring in unconventional films that show his grizzled side, such as 'Babel.' And through Plan B, he is producing edgy projects including 'Running With Scissors' and the current box office hit 'The Departed.' He's also producing ''A Mighty Heart,' starring girlfriend Angelina Jolie, 31, as the widow of murdered reporter Daniel Pearl.

In 'Babel,' Pitt plays a helpless husband who tries to save his wife, who is accidentally shot while on a tense vacation in Morocco. Variety praises Pitt for giving his character 'weight and strength,' and the Hollywood Reporter calls his performance 'committed.'

Bring up Pitt's name to anyone associated with him, and you hear stories of personal thank-you notes, congratulatory e-mails and a level of thoughtfulness unusual in a star of his caliber.

'Brad is not pretentious. There's nothing artsy-fartsy about him,' says 'Running With Scissors' director Ryan Murphy. 'Brad is incredibly enthusiastic. I heard he'd liked the script, and I met him at the [production] offices, and here come these handmade Prada shoes with Brad Pitt attached. He said something to me like, 'You've got wicked skills.' '

That unaffectedness, says Simon Kinberg, who wrote the 2005 hit 'Mr. & Mrs. Smith,' 'is kind of an amazing thing. It's not a game or strategy with him.'

In particular, Kinberg remembers one long day of shooting when the exhausted cast and crew had worked into the night and saw no end in sight.

'Brad, out of the blue, started doing jumping jacks, calling out to the crew, getting everyone's spirits up at 4 a.m. at some awful diner in downtown L.A.,' Kinberg says. 'He was the guy who would cheerlead for the movie -- and he didn't have to. He's the top, and the energy flows from the top down.'

Pitt doesn't mind looking less than perfect. In 'Babel,' he goes gray and has bags under his eyes.

This isn't a star with blockbuster on the brain. Ever since he stole hearts in 1991's 'Thelma & Louise,' he has had hits (1995's serial killer drama 'Se7en,' last year's 'Mr. & Mrs. Smith'), but just as many misses (1997's ''Seven Years in Tibet,' 2004's 'Troy'). He has earned one Oscar nomination, for his supporting turn in 1995's ''Twelve Monkeys.'' These days, Pitt mixes it up. He took a pay cut for 2007's 'The Assassination of Jesse James by the Coward Robert Ford,' but he's also reprising Rusty Ryan in the third 'Ocean's'' installment, due in June.

Film historian Leonard Maltin applauds Pitt's willingness to 'sacrifice some of his movie-star persona for the sake of a really good part. What we're seeing is his willingness, if not downright eagerness, to challenge himself with more demanding and daring roles.'

And that gets major props from Darren Aronofsky, who was ready to direct Pitt in ''The Fountain'' before the actor dropped out because of creative differences.

'Brad's a great guy, and we're still friendly. We're OK with the breakup,' Aronofsky says. 'Brad's a really smart, very talented guy. He's come to a place in his work where he's doing interesting stuff. He's looking great. The pretty-boy thing wasn't my type of hetero joy. I like the wizened Brad now.'

Others appreciate his taste for the unconventional, such as his decision to executive-produce the documentary 'God Grew Tired of Us: The Story of Lost Boys of Sudan.' Writer/director Christopher Quinn had run out of money and says that, without Pitt's help, the movie would likely not have been made. Quinn, introduced through mutual friends, met Pitt at his home.

The meeting was casual and Pitt was disarming. But, Quinn says, he 'has incredible follow-through. When we won [two awards] at Sundance, he sent me a note saying how proud he was to be a part of the movie.'