As a horror movie "freak," I am not very picky about defining any movie as being the best. That said, one needs to consider the different characteristics defined when one is considering a movie good or not.
First, some people simply love the "blood and gore" depicted in most horror movies. In this category, I love Hostel, Saw (the entire series), and Zombieland.
When looking at pure fear factor, some of the horror movies which are wonderful are Inception, The Skeleton Key, and The Grudge.
There are other movies, included in the horror genre, which can be defined as containing multiple aspects (gore, fear, suspense, etc.). Perhaps my favorite horror movies are Frankenstein, Dracula, and Interview With a Vampire. Given my background in literature, I find that the filmatic adaptations of these movies are well completed.
I have to, also, bring up some of the classic horror movies: Whatever Happened to Baby Jane, American Psycho, and the original Nightmare on Elm Street.
After the first viewing of the 1974 original--now a cult B classic--The Texas Chainsaw Murder, I felt that the movie was frightening and graphically horrible. However, after I watched it a second time, I realized that there is a psychological study to the movie that increases and dimensionalizes the horror. For, the chainsaw operator wears a mask made from human skin and he mimics the mother, wearing aprons and whining in a high pitch. Curiously, there are no females in the deranged family, so, perhaps the man in the mask substitutes himself in the female role. This version is the only one that portrays this role-playing, also.
As a point of fact, there is a prisoner who was in the cell next to the big man who wore the woman mask. He said that for all the several years, the man never said one word--also, a curious and intriguing fact.
I liked The Raven. I recently watched it again on DVD, but I saw it in May in the theater. I am a great fan of Edgar Allen Poe. I like the fact that it is kind of smart, and allows fans of Poe to enjoy seeing the stories come to life. They are gory, so reading about them is one thing and seeing is another. The movie is rated R, and there is blood and some gross scenes, but on balance it’s not that bad.
The Paranormal Activity films are popular for a reason. Speaking personally, I have been very impressed by the successful creation of prolonged suspense in these movies.
Through very simple and subtle means of forced anticipation, Paranormal Activity 1, 2, and 3 each had me on the edge of my seat.
I'd also recommend The Blair Witch Project, Ringu, and Ju-On.
You mention funny: Go no further than Young Frankenstein, by Mel Brooks. It's not very scary, but the laughs never stop. I showed it to a group of students who had never seen it before (as part of a sci-fi class), and it was received better than nearly any movie I'd ever shown. For me, the scariest movie I ever saw was the original The Exorcist, though it certainly isn't in the horror genre.
If you want a funny, yet still scary horror movie may I suggest any of the Scream movies and also Cabin in the Woods.
I think that the original 'ring' is Japanese and not Korean.