After his time on television, he appeared in a number of movies, most notably "Problem Child" and its first sequel. He played the lead role in Blake Edwards' 1989 film "Skin Deep", appeared in the film version of "Noises Off", rejoined Billy Bob Thornton in the Oscar-winning "Sling Blade" (playing a kindhearted, gay, discount-store manager), and co-starred with Olivier Gruner in the 1996 action film "Mercenary". Ritter starred in many made-for-TV movies, including "Gramps" (1995), co-starring with Andy Griffith, Rob Hedden's "The Colony" (1995) with Hal Linden, Stephen King's "It", "Danielle Steel's Heartbeat" with Polly Draper, and "It Came From the Sky" in 1999 with Yasmine Bleeth. Ritter also made guest appearances on television shows, such as "Felicity", "Ally McBeal," "Scrubs," "Buffy the Vampire Slayer", and an episode of "" (2002). He also provided the voice of the title character in the animated children's show "Clifford the Big Red Dog" and its animated film adaptation "Clifford's Really Big Movie" (2004), a role for which he received four Emmy nominations. His final film was "Stanley's Dinosaur Round-Up" (2006), an animated direct-to-DVD film based on the television series, which was dedicated to his memory. At the time of his death, he was starring in "8 Simple Rules for Dating My Teenage Daughter".