Although some of his longer stories, such as the Call of Cthulu, are pretty good too, however my favorite of his stories is a short story called...Damn, I forgot its name. But it is about this old man, who should have died years ago but is still alive and very sick. And like something in his apartment breaks and some young dude has to come to fix it, and his apartment is freezing. But like towards the end of the story the old man dies because the air conditioner breaks and the only thing keeping him alive was the cold temperature of the room and when it heated up he died. It is very interesting. I believe it is the first or second story in HP Lovecraft's book Waking Up Screaming. Check it out if you like horror with a science-y feel to it. (:

Pretty much all short stories by HP Lovecraft are amazing.