The first film was a breath of fresh air. I am a horror fanatic, and the genre needed that film at the time. They went to the Jigsaw well too many times and ruined it for me. I watched III in the theater and after that, washed my hands of the franchise. I watched Saw IV online, and still haven't watched V and have no plans to watch VI. Quicker this franchise dies off, the better.
The franchise went from being good, original horror to being one of the main things wrong with the genre.