Books and Short Stories
"The Colour out of Space," by H.P. Lovecraft
"The Shadow Out of Time, by H.P. Lovecraft
"Call of Cthulhu," by H.P. Lovecraft
Ender's Game by Orson Scott Card
Neuromancer by William Gibson
Lies, Inc. by Phillip K. Dick
Ringworld by Larry Niven
The Dark Tower (series) by Stephen King
Film and Television
Firefly and Serenity - A series blending spacetravel and the old west. If you haven't seen Serenity or Firefly, it'd be a good idea.
Iria - This is an anime series about a girl who's a member of a bounty hunter guild in the far future, chasing after a horror that was uncovered by science.
The Fifth Element – Most people have seen this. The sort of dystopia is kind of similar to how most colonies work in the Confederated Human Worlds.
Pi - A mathematician discovers the name of God and is chased by strange corporate entities, which leads me to…
Inception - Wherein a dream engineer pulls off one of the greatest heists of his career to achieve a free life. This is where most of the Intergalactic Communications Network came from, considering that it's built out of all users' subconscious minds.
Dollars Trilogy – Classic western series by Sergio Leone, starring Clint Eastwood as the Man With No Name (Fistful of Dollars, For A Few Dollars More, The Good, The Bad, The Ugly). See above regarding Firefly. This series of films explains the way that law works on most colonies in the Confederated Human Worlds. Most people live and die by the gun.
Star Wars IV-VI – Yup.
Mass Effect – Kind of goes without saying. A lot of the way that the galactic council operates was taken from this. Intrigue, politics, violence, etc.
Dead Space – In the far-flung reaches of space, a human mining colony discovers an artifact and takes it aboard the ship. Suddenly, all contact is wiped out. Sound familiar? Also, be sure to check out Dead Space: Downfall, the anime prequel to the game and Dead Space: Aftermath, which discusses the fate of the survivors of O'Bannon.
Murder By Death
The Reverend Horton Heat
The Builders and the Butchers
Margot and the Nuclear So and So's