I liked the Halloween series though to be honest I was disenchanted with it after suffering through H20. Also after watching House of 1000 corpses I'm certainly in no hurry to see another movie directed by Rob Zombie... seriously he should stick to music.
I've always found jigsaw's psychology to be twisted genious. The traps and deaths in this film were well thought out in typical saw style. This movie is a great horror flick for those who like blood and gore and is also a great storyline littered with psychosis for those who like to digest movies. This is probably the first 4th movie in a series that I found to be just as strong as the first movie.