Heath Ledger should win an oscar

"I can only speak superlatives of Ledger, who is mad-crazy-blazing brilliant as the Joker," Rolling Stone critic Peter Travers writes.

"It's typical of Ledger's total commitment to films as diverse as Brokeback Mountain and I'm Not There that he does nothing out of vanity or the need to be liked," Travers continues.

"Ledger's Joker has no gray areas — he's all rampaging id," the critic says. "He creates a Joker for the ages"

"No plastic mask for Ledger," Travers describes. "His face is caked with moldy makeup that highlights the red scar of a grin, the grungy hair and the yellowing teeth of a hound fresh out of hell."

Travers says the performance makes him an Oscar contender.

"If there's a movement to get him the first posthumous Oscar since Peter Finch won for 1976's Network, sign me up," he writes.

The actor – who died at age 28 of an accidental overdose of prescription drugs in January – will be honored in the end credits of the film.

(Click here for a photo retrospective of Ledger's life.)

Ledger will be acknowledged along with Conway Wickliffe, a special-effects technician on the film who died in a stunt in September.

"In memory of our friends Heath Ledger & Conway Wickliffe," the credit reads, according to Warner Bros. publicity Web site.

(See Us' photo tribute to stars who have gone too soon.)

Dark Knight star Christian Bale opens up about working with Ledger in the new issue of Parade.

"He was a unique character, a very infectious character," Bale says. "He was a good man, and I was glad to have spent time with him."

The film opens July 18.