Movies:
* One Flew Over the Cuckoo's Nest (1975) - This iconic film marked his breakthrough role as the mentally disabled Billy Bibbit.
* The Lord of the Rings: The Fellowship of the Ring (2001), The Two Towers (2002), The Return of the King (2003) - He voiced the creepy and sinister Gollum.
* Dune (1984) - He played the sadistic Baron Harkonnen.
* Child's Play (1988) - Through Child's Play 7 (2018) - He voiced the infamous killer doll Chucky, becoming synonymous with the role.
* The Silence of the Lambs (1991) - He played the creepy and eccentric serial killer, Hannibal Lecter's cellmate, "The Tooth Fairy".
* Deadwood (2004) - He played Doc Cochran.
* The Texas Chainsaw Massacre: The Beginning (2006) - He played Leatherface's father.
* The Grudge (2004) - He played the ghostly and terrifying Peter.
* Alien: Resurrection (1997) - He played the android, Call.
* Curse of Chucky (2013) and Cult of Chucky (2017) - He continued voicing the iconic Chucky in these direct-to-video sequels.
* The Wrong Turn (2003) - He appeared as an inbred cannibal.
Television:
* Deadwood (2004-2006) - His portrayal of Doc Cochran earned him an Emmy Award nomination.
* The X-Files (1995-2002) - He played the role of the "Squatter" in the episode "Squatter"
* The Walking Dead (2012-2013) - He appeared as Merle Dixon's father, Earl.
* Star Trek: Deep Space Nine (1995-1999) - He voiced Weyoun.
* The Twilight Zone (2019) - He played the role of a mysterious old man in the episode "The Traveler".
* The Mandalorian (2022-present) - He played the mysterious, "Prisoner."
* The Last of Us (2023) - He played the role of "Frank".
Beyond these, he has appeared in numerous other movies, television shows, and video games.
Note: This is not an exhaustive list, but it highlights some of his most recognizable and impactful roles. Brad Dourif has a lengthy and diverse filmography that continues to grow.