Ghostbusters

Who ya gonna call?

Ghostbusters is a 1984 comedy film directed by Ivan Reitman and written by and starring Harold Ramis, Dan Aykroyd and Rick Moranis. It is about three former parapsychology professors (played by Ramis, Aykroyd and Bill Murray) who form a ghost extermination service called "Ghostbusters". The film had a sequel, reboot and two animated series. The Brothers Chaps sometimes slip references to this movie and its spin-offs in Homestar Runner cartoons.

References

Homestarloween Party — Pom Pom's costume is Stay-Puft Marshmallow Man, a character from the movie.
Email ghosts — Strong Bad and The Cheat wear Ghostbusters II T-shirts while looking for ghosts.
That A Ghost — Old-Timey Marzipan and The Homestar Runner quote a line from the movie: "Let's split up, we can do more damage that way".
In Limozeen: "but they're in space!", Mary Palaroncini is drawn with red hair and is fat, similar to Dan Aykroyd's character from the The Real Ghostbusters.
An Important Rap Song — The page title, "We now return to the REAL Cheat Commandos!", references The Real Ghostbusters.
Email business trip — "You— you've earned it" is quoted by Strong Bad when rewarding Homestar Runner. Peter Venkman (played by Bill Murray) delivers the line while rewarding Egon Spengler (played by Harold Ramis) with a Crunch Bar for discovering how to "catch a ghost and hold it indefinitely".