H.P. Lovecraft with all his unspeakable horrors, indescribable oddities and non-euclidean angles never really helped any visual artists, uhh, visualize his stories and -apparently- that's one of the reasons many -mostly Cthulhu- HPL inspired games failed to capture that distinctly Lovecraftian atmosphere and/or cosmic horror. The fact, mind you, that most of his protagonist were on the asthmatic academic side of humanity didn't help with the necessary video game action bit either.
Interactive fiction (text-adventures) and HPL's kind of horror, on the other hand, seem like a match made in a particularly tentacled heaven. Don't believe me? Why, better try the excellent freeware Anchorhead and see what I mean. Good writing, vaguely described ominous things and interactivity, without the distraction of anavoidably underwhelming visuals, make for quite an experience. And atmospheric horror too of course. Problem is such games are rather rare and The Lurking Horror is almost ancient history.
Enter the Illuminated Lantern, interactive fiction publishers extraordinaire, creators of the award winning 1893: A World's Fair Mystery and driving
force behind the Commonplace Book Project. The purpose of said project is both simple and frankly quite noble: create interactive adventures based on the unfinished story ideas that H.P. Lovecraft collected in his "Commonplace Book". The first seven games (including Dead Cities, Ecdysis, The Cellar and the Handyman Wanted point-and-clicker) have already been made available here and are ready to provide you with hours of relatively disturbing entertainment. For free. Hip, hip...
Oh, and Windows users will probably have to download the excellent and very freeware Gargoyle interactive fiction player. Possibly even have a look at a beginner's guide to interactive fiction.
Related @ Gnome's Lair: Text is King, Guide to the indy adventure, Vilyl LP text adventures, lovely i-f maps