Kids, dogs and this person: ten actors who stole scenes in films with the lead giving a career performance.

James Mason is in the midst of giving a powerfully tragic performance in Odd Man Out as a wounded IRA operative when Robert Newton makes his entrance as Lukey a deranged, drunken artist intent on painting a dying man's picture. In sharp contrast to the withdrawn Mason, Newton's rages never let up as director Carol Reed utilizes his energy to take this masterpiece in another direction and infuse the films momentum.

Harvey Keitel has the lead in Martin Scorcese's breakout masterpiece Mean Streets but it is Robert De Niro in his first mainstream film as the off the wall Johnny Boy that engenders the most emotion over the course of the film. Though Scorcese's camera sticks to Keitel most of the film DiNero's unpredictable punk forces you to take notice. Keitel would return the favor in Taxi Driver, playing a pimp with hipster elan to DiNero's loose cannon Bickle.

In Five Easy Pieces Jack Nicholson is giving the best performance of his early career featuring some fierce naturalistic acting when he picks up Kallianiotes and a friend hitch hiking. Dispersed over fifteen minutes she launches into a tirade on a variety of topics on what's wrong with the world with a dead pan passion that monopolizes the screen the entire time she's on it.

Victor McLaglen's purnacious Gypo Nolan bullies, blathers and bleeds his way to an Oscar in The Informer rightfully remaining center stage throughout until Donald Meek as the accused Mulligan states his case before a tribunal whose fate they hold in their hands. Meek at first chastened and not feeling well meekly states his case but when queried to his whereabouts launches into a convoluted explanation gaining confidence as he does and throwing the utter gravity of the scene into mild comic chaos.

James Mason is once again interrupted in mid greatness (see Robert Newton above) as Humbert Humbert in Lolita by Peter Sellers as nemesis Quilty. The multi faceted Sellers launches into a series of comic poses as he frustrates and derails Humberts intentions with a touch of comic sadism and while it doesn't diminish Mason's magnificent performance it adds as worthy adversary.

In The Manchurian Candidate Laurence Harvey's giving an Oscar nominated performance and Frank Sinartra ain't having too bad a day as well but it is Angela Lansbury as Larry's homicidally ambitious mom that delivers one of the most riveting female performances in film history. Her pep talk to Laurence Harvey to go out and assassinate one for mom is one of the most coldly powerful moments up until that time in film history.

Alice Adams is widely considered Katherine Hepburn's finest early roll. Comic and bittersweet Hepburn gives a touchingly somber performance throughout but the films most memorable moments belong to Hattie McDaniel as the housekeeper having to deal with Alice's pretentious and pathetic social climbing. Perforating the faux pomposity of Alice with glances and actions she upstages Hepburn nearly every second they share a scene.

Peter Sellers is having a field day playing three characters in Dr. Strangelove but when confronting Sterling Hayden's gone rogue military commander Jack D. Ripper Sellers' Mandrake must defer to Hayden's paranoid ravings. Strangelove was filled with a crowded field of scene stealing moments provided by George C. Scott, Slim Pickens and Keenan Wynn but Hayden's remains the most memorable with his stoic caricature having a bit more chilling undertone about him.

Scott could be mentioned three times on this list with Strangelove above and some potent moments going up against Jimmy Stewart in Anatomy of a Murder but in The Hustler he runs the table against oscar nominated Paul Newman. Scott trumps one of Newman's finest performances with an intensity and passion for greed that tilts the attention to him in every scene they have together. Piper Laurie also giving a career performance holds her own against Scott a little better but Scott's convincing deviousness of curt cold explanation and darting eyes remains at the center of every scene he shares with the leads.

In Viva Zapata Marlon Brando gives one of the finest performances of his career by bringing noble countenance to the role of Mexican revolutionary Emiliano Zapata. Counterpointing Brando's subdued passion and purity Anthony Quinn as brother Eufemio let's it all hang out with Bachanalian brio as he womanizers and boozes (as well as ride a horse better) his way through the Mexican Revoluton aside his more restrained contemplative brother. Brando may be at the center of Zapata but in their final scene together Quinn who has been contributing mightily from the edge takes center stage.