The Wilhelm Scream, a specific sound effect of a man crying out, was originally produced for the 1951 film Distant Drums. It has since become a ubiquitous sound effect in films, and has become a sort of inside joke for audio engineers and cinemaphiles. At least part of its popularity can be credited to sound designer Ben Burtt, who included it in every Star Wars and Indiana Jones movie. Its influence has more recently extended beyond films, and has appeared in a number of video games, from Twisted Metal 2 to more modern games like Metal Gear Solid 4 and Grand Theft Auto IV.
The Wilhelm's revival came from Star Wars series sound designer Ben Burtt, who tracked down the original recording (which he found as a studio reel labeled "Man being eaten by alligator" ). Although Distant Drums was the first known use of the scream, Burtt named it after "Pvt. Wilhelm", a minor character who uttered the same scream in the 1953 film The Charge at Feather River.
Although it is not known for sure who recorded the Wilhelm Scream, the most likely voice actor was musician Sheb Wooley who is most famous for the song "Flying Purple People Eater". He was on the short list of actors who recorded certain additional voice elements for Distant Drums. Also, in 2005, his widow, Linda Dotson said it was Wooley's scream and added that he had always joked how good he was at screaming and dying in films.
The Wilhelm scream is available here.