I love John Carpenters halloween. Its such a simple movie but very effective. Even down to the theme which John Carpenter scored its so simple but puts you on edge.
The second part was okay but the rest of the series were terrible particularly season of the witch.... it didnt even have Mr Myers in it and was about masks WTF I still feel cheated after buying that DVD - bastards
The remakes are very good in my opinion. I agree that they are more complex than the originals, they fill the blanks in and expand the story. They turn "the shape" in to a person. More like a psychotic serial killer than a faceless almost paranormal being.
He doesnt just stab you once and then watch you die slowly he repeatedly slashes and stabs and generally butchers... its why I like the original texas chainsaw massacre. Its not a movie you can walk away from and think "it was a scary monster that doesnt exist". You walk away thinking that could be any remote part of the world with a bloke who could slaughter you... hang you on a hook alive while you watch him fire up his chainsaw and begin to chop you up alive.
For atmosphere I also really like John Carpenters "The Thing". Simple music, again by Mr Carpenter, very atmospheric and a feeling of isolation and hopelessness. Great movie.