I love Cthulu and Lovecraft - so creepy. Long before I actually read any of it, though, someone DMd an adventure that I figured out afterwards was actually based on the mythos - involving a mysterious old seaside town and strange sea creatures (which did not make an appearance til well into the adventure). It was a fun adventure (wholly made up) by a guy who is now a professional playright (and he has had many plays produced). Though, sad to say, I've not seen any of them, as they are all far away from me.