John Carpenter's Apocalypse trilogy is three films, over thirteen years, which on the surface seem to have nothing in common, other than being in the trilogy together. While each film is different, they all take influence from Lovecraft, and all share an apocalyptic threat to mankind.
The Thing 1982
The first being The Thing, in which an ancient alien that has the ability to imitate any life form perfectly is awakened and set loose on a research base in the Antarctic. Filled with great gore, and one of the greatest understated endings in horror cinema, The Thing shows an end for mankind in which we'd all be taken over by it.
Prince Of Darkness 1987
Prince Of Darkness is the tale of a group of students who are brought together to figure out what a malevolent tube of glowing green stuff is. While Prince Of Darkness plays on Christian theories of God, and the Devil, turning them on their head, if you change your point of view, and drop the idea of it being religious, you have a perfect example of Lovecraft inspired cosmic horror.
Prince Of Darkness shows a world where god is evil, what more of an apocalypse could there be?
In The Mouth Of Madness 1995
In The Mouth Of Madness follows John Trent, who is tasked with finding misng author Sutter Cane, a horror writer who's works have been driving people crazy. ITMOM is the most heavily drawn from Lovecraft, of the trilogy, with every location, character, and events being lifted from a Lovecraft story in some way. ITMOM shows a world where our perceptions of reality were never correct to begin with, and are much darker than we could of ever imagined