With “Tropic Thunder” triple-threat Ben Stiller is inching closer to a work befitting the eviscerating talent of “The Ben Stiller Show,” his scything skit show which Fox deigned to broadcast for a measly 12 episodes in the fall of 1992.   Filled with brutal parody and sharp yet sophomoric satire in sketches such as “Ask Manson,” “Tito Gallegos, The Pig Latin Lover,” and “TJ O’Pootentoot,”  the show’s sensibility seems a far cry from Stiller’s recent resume where he has spent too much time playing the befuddled every guy in other folks’ half-hearted efforts such as  “Meet the Fockers,” “Along Came Polly,“ “Night at the Museum,“ and “The Heartbreak Kid.“ Even Stiller’s last directorial effort — “Zoolander”  — felt both as a film and performance like a bit of a sleepwalking exercise. So, it’s encouraging that as director and co-screenwriter he’s added a bit more nuance and bite to his comic creations in one of this year‘s more notoriously talked about films.  

At times discomfitingly funny, “Tropic Thunder” follows a troupe of self-obsessed actors filming a Vietnam War opus on location in Southeast Asia who anger their director and producer so thoroughly that they are unwittingly dropped into the jungle to teach them a quick lesson. Suddenly, events conspire to maroon the quintet led by Tugg Steadman (Stiller), a preening action hero grasping for greater depth in his career.  

Beginning with savagely clever and inspired parody trailers of each of the actor’s seminal work, “Tropic Thunder” is an equal opportunity offender. Almost every sector of society is mocked. (Don’t worry Kazakhstan, you’re spared this time.) But Hollywood is the bull’s-eye target, with the industry’s penchant for honoring actors for portraying people with disabilities earning particular scrutiny. You will swear you’ve seen Stiller in “Simple Jack.”

In the role of five-time Oscar winning Australian method actor, Kirk Lazarus, who undergoes skin pigmentation surgery to play African-American Sergeant Lincoln Osiris,  Robert Downey Jr.  delivers a performance for the ages. Forgetting the brazen courage to attempt the part, what about the chops? He exhibits immense dexterous talent by portraying a black man who is completely self realized and devoid of caricature. Somewhere C. Thomas Howell is bowing his head in shame.

Future editions of Eila Mell’s “Casting Might-Have-Beens” won’t be troubled by stories of the various actors Stiller would have had in mind for the role. It had to be Downey or bust. He’s so good you begin to wonder, “What can’t he tackle?”  The Michael Phelps Story?  A live-action Cartman, Kyle and Kenny? “The Queen”?  In 2008, Downey’s work has been so exemplary that perhaps next spring the Academy should bestow a best supporting nomination on his close friend, personal assistant and “sponsor,” Jimmy Rich.  There’s more to come from the iron man later this year as he costars with Jamie Foxx in Joe Wright’s anticipated drama, “The Soloist.” I wouldn’t bet against a trifecta. As to the future, he’ll appear on screens in 2010 as Sherlock Holmes in a Guy Ritchie project, thereby snatching the director’s career from oblivion.

Jack Black, so unselfconsciously demented in the under-the-radar and underappreciated “Be Kind Rewind,” leavens the outrageousness with a muted turn as Jeff Portnoy, a drug-addled comic actor who bears a faint resemblance to Chris Farley.  However, Black bursts out of this cocoon in a detox scene which is brutal, gut-busting and instantly quotable.

Aside for the main trio, the expansive cast  performs with varying degrees of success. Brandon T. Jackson, as rapper Alpa Chino, and Jay Baruchel, as earnest young actor Kevin Sandusky, are welcome additions to the cast-adrift actors. Matthew McConaughey as Tugg’s agent displays charm and comic timing with such aplomb that you hope he will fire his own, expand his repertoire and stop making foolish films with that Wasa of actresses, Kate Hudson.

As the author of the film’s war-time memoir, Nick Nolte is so grizzled you’d think he’d supped on a dinner of Sam Elliott and Eli Wallach. Danny McBride, the flavor of the month, doesn’t do much with his pyrotechnics wizard role and you ponder if the buzz about this dude might be bong induced. Similarly, Steve Coogan feels slightly underutilized as the film’s put-upon director. But Tom Cruise clearly revels in the raunchy role of the film’s megalomaniacal producer with a look suggesting a homicidal James Lipton. He also sports the gnarliest hand hair in recent screen memory.

In a bit of deflating news, according to reports, Stiller and Cruise are teaming up in “The Hardy Men,” updating the Parker Stevenson and Shaun Cassidy pairing to adulthood. It sounds like a “Focker” nightmare so unless there’s an inspired twist to this scenario, I fear that in his career we will only see the comic best that Stiller can conjure in fleeting snippets. If true, he‘ll justifiably become “The Heartbreak Kid.”