With a career that spans seven decades, Robert Duvall (born on January 5, 1931) has a filmography any actor would kill for. His legendary career began in theater and television, with notable appearances on shows like The Twilight Zone and The Outer Limits before he'd transition to feature films. Duvall has appeared in some of the greatest films ever made and would win a Best Actor Oscar for his role as an alcoholic country singer in 1983's Tender Mercies. That film won't make this list, but let's look at the ones that do.

5 MASH (1970)

MASH- Robert Duvall
Distributed by 20th Century Fox

Robert Altman's hit 1970 black comedy may have taken place during the Korean War, but it contains many allegories for the Vietnam War. The movie would inspire a successful TV show of the same name, running from 1972-1983, and whose finale had viewership numbers only surpassed by Super Bowls. The film centers around a Mobile Army Surgical Hospital (MASH), who gets two new surgeons: "Hawkeye" Pierce (Donald Sutherland) and "Duke" Forrest, who arrive in a stolen army Jeep. Competent surgeons they may be, but they're also insubordinate womanizers, a direct clash with Robert Duvall's more straight-laced and religious Frank Burns. Burns is one of the many victims of Hawkeye's and Duke's pranks, the most serious of which is when they rile Burns up enough to punch out Hawkeye, causing him to be taken away for a psych evaluation. That's one way to get out of a war.

Related: The Best Vietnam War Movies, Ranked

4 Apocalypse Now (1979)

Apocalypse Now Kilgore
United Artists

Based on Joseph Conrad's anti-colonial novel, Heart of Darkness, Francis Ford Coppola's 1979 masterpiece transports the action from the Belgian Congo to the Vietnam War. After US Army Special Forces Colonel Kurtz (Marlon Brando) appears to have gone insane and established a base in Cambodia, Captain Benjamin Willard (Martin Sheen) is given the task of hunting him down and terminating Kurtz's command... with extreme prejudice. Along the way, Willard and his team rendezvous with a helicopter-based assault unit led by Duvall's character, Colonel Bill Kilgore. Kilgore is... an interesting duck, to put it charitably. He bonds with one of Willard's men over a shared love of surfing, and he enjoys blasting Wagner's "Ride of the Valkyries" before an airstrike. Kilgore also gets the film's most iconic quote, "I love the smell of napalm in the morning." It's the beginning of a great monologue where Kilgore sums up his philosophies on war and even suggests a little sadness in the man when he realizes the war will eventually end. It's incredible work by Duvall, and he was rewarded with a Best Supporting Actor Oscar nomination for his work. Should've won for it, too.

3 To Kill A Mockingbird (1962)

To Kill A Mockingbird- Mary Badham and Robert Duvall
Distributed by Universal Pictures

This classic 1962 movie, based on Harper Lee's classic Pulitzer Prize-winning novel of the same name, is a coming-of-age story centered around Scout Finch, a young girl in 1930s Alabama. Her father, lawyer Atticus Finch (Gregory Peck in an Oscar-winning performance) defends a black man (played by Brock Peters) falsely accused of sexually assaulting a white woman. The film is Duvall's feature film debut, and admittedly, his part is rather small. He plays Boo Radley, the enigmatic and rarely seen neighbor of the Finches. After the trial where Atticus implies the woman's father, Bob Ewell, was the one who attacked her, Radley appears to save Atticus' children from the vengeful Ewell and kills the man in the process. Duvall's completely silent, but his eyes and facial expressions tell us everything we need to know about this reclusive, but ultimately kind man.

Related: The Offer: Things We Learned About the Making of The Godfather

2 The Godfather and The Godfather, Part II

The Godfather- Robert Duvall
Distributed by Paramount Pictures

One of the best mobster movies ever made, one of the best American movies ever made, an instant classic. Which of the two films are we discussing? Both of them. These two films are so iconic and have made such a huge cultural impact and Duvall was there for both of them. He plays Tom Hagen, a lawyer who serves as the Corleone crime family's consigliere, which makes him a top advisor to the head of the family. An adopted son of the family (he's of German-Irish descent), Hagen advises both Vito Corleone (Marlon Brando) and later, Michael Corleone (Al Pacino). However, his non-Italian ancestry means he'll never be a formal member of the family. Duvall is incredible in both films, though he only received a Best Supporting Actor Oscar nomination for the first (He lost to the wholly deserving Joel Grey for Cabaret). Calm, cool, collected, Hagen is a direct contrast to the hot-headed Sonny (James Caan) in the first film. Contract disputes prevented Duvall from appearing in The Godfather Part III.

1 Network (1976)

Network - Robert Duvall
United Artists

This fantastic 1976 satirical black comedy-drama movie was written by Paddy Chayefsky (who would win his third Screenplay Oscar for it), and directed by Sidney Lumet. The story centers around a fictional TV station known as UBS, where one of its longtime anchors, Howard Beale (Peter Finch, who would win a posthumous Best Actor Oscar for his performance), has fallen into depression and alcoholism and goes on an on-air tirade on what he believes will be his last ever newscast. However, Beale's tirade proves to be a ratings' bonanza, and the programming chief, Diana Christensen (Faye Dunaway, who alongside Finch, won an Oscar for her performance), decides to exploit Beale and give him his own show where he can rant and rave about whatever he pleases. Duvall plays Frank Hackett, Christensen's boss who goes along with her scheme to exploit Beale. The dialogue flies like machine gun fire and every actor keeps up, including Duvall. After watching this movie, you'll be shocked to discover he wasn't nominated for a Best Supporting Actor Oscar for his incredible performance. A prophetic movie, Network just barely ekes out the Godfather films for the best film Duvall has ever been in.