Playing Amnesia got me longing for more Lovecraftian horror, so i recently ended up renting and watching some horror movies made after his most known stories. Some of them are older and the effects are a bit "silly" from today's cinema standards point of view, but if you like Lovecraft than maybe it will be of relevance if I recommend a few which i liked the most.
The oldest ones are the
Re-animator (a triology) which is also pretty funny,
From Beyond and
The Curse.
Next good ones are
The ressurected and
Necronomicon, then there is also
Bleeders and
Dagon.
The closest match to the actual story is
The call of Cthulu which was made by an independant group of Lovecraft enthusiasts; it is a black&white silent movie but very well made nevertheless.
I would also recommend Carpenter's
In the mouth of madness; although not directly made after a story, it contains a lot of lovecraftian elements and is also quite disturbing