Made professional acting debut on stage at the Edinburgh Festival in Scotland
Film acting debut in "The Barefoot Executive"; billed ninth
Made TV debut as a guest in an episode of ABC's "Dan August", starring Burt Reynolds
Had role of Reverend Fordwicke on the CBS drama "The Waltons"
TV-movie debut in "The Night That Panicked America" (ABC)
Co-starred in Peter Bogdanovich's "Nickelodeon"
Starred in the popular ABC sitcom, "Three's Company"
Hosted the ABC variety special "John Ritter: Being of Sound Mind and Body"
Had one of the leads in Bogdanovich's ill-fated "They All Laughed"
Hosted the syndicated special "The Singing Cowboys Ride Again"
Headed the cast of the spin-off sitcom "Three's a Crowd" (ABC)
Delivered strong dramatic performance as a Vietnam veteran who may be suffering from the effects of Agent Orange in the NBC TV-movie "Unnatural Causes"
Had title role in the ABC half-hour comedy-drama "Hooperman"
Formed Adam Productions
Executive produced the first season of the popular ABC sitcom, "Anything But Love"; also played recurring role on the series as Richard Lewis' nemesis
Executive produced the short-lived sitcom, "Have Faith" (ABC)
Co-starred in the ABC miniseries "Stephen King's 'IT'"
Had title role in the NBC biopic "The Dreamer of Oz: The L. Frank Baum Story"
Played the surrogate father of the "Problem Child"
Reprised role in the sequel "Problem Child 2"
Starred in the CBS sitcom "Hearts Afire"; first screen collaboration with Billy Bob Thornton
Had third teaming with Bogdanovich with the backstage comedy "Noises Off"
Delivered a change of pace performance as a gay man who befriends a co-worker in Billy Bob Thornton's "Sling Blade"
Had recurring role as a client-turned-love interest for Calsita Flockhart's "Ally McBeal"; earned an Emmy nomination
Made Broadway debut co-starring with Henry Winkler in "The Dinner Party", a comedy written by Neil Simon
Starred in the L.A. production of the play "J for J", writer-director Jenny Sullivan's autobiographical play about her developmentally disabled older brother
Starred in the ABC comedy series "8 Simple Rules"
Played Bob Chipeska, a department store manager in "Bad Santa"; movie released after his death
Voiced Clifford in the animated feature "Clifford the Big Red Dog"; movie released after his death
Received an Emmy nomination ten months after his death for Best Actor in a Comedy Series for his work on "8 Simple Rules for Dating My Teenage Daughter"