I love all movies in the series, it's my favorite franchise ever and so far it has been perfect. But Saw will always be my number one.

I like the third one the best :D

Just my opinion:
- The first Saw movie had a few traps that were just stupid and unfair, mostly the Flammable Jelly trap with Mark. Its budget limitations aren't my problem, but the limits of the story are.
- Saw 3 is unfair, overly torturous, and sometimes very stupid. I don't mind torture, but in these traps, it is definitely not justified. Why does a young guy who accidentally ran over a kid and felt extremely sorry and sad deserve to have his limbs twisted and broken slowly? Pure bs to me.
- Saw 4 is quite dumb to me. Because the trap plot isn't contained in some isolated building, it's now some overcomplicated quest. Daniel Rigg is targeted, for wanting to save people, which is just more pure bs. Also, he can just do whatever he wants in the next 90 minutes. If he avoids all the traps and just goes to some bowling alley, a bar, and Burger King, he can wait out those 90 minutes. Also, I did not find the Art Blank story to be interesting at all.
- Saw 5 is fine, but the trap plot feels more like a subplot, since it doesn't connect to the main story until the end. And the main plot is just average to me.
- Saw 6 is my 2nd favorite in the series, but I like Saw 2 more because the trap plot is the main plot in that film.
- Saw: The Final Chapter has good intentions, but it plays out like a self parody at times, with it's poor attempts at a horror tone, the overexaggerated plot, the pink blood, and the funny 3D effects. Also, it's underwhelming for a supposed finale.
- Jigsaw is the worst of the series to me. Not only are the characters not as interesting, but the plot twist at the end is so convoluted, it's hilarious. Plus, most of the traps are overly complex and only happen due to convenient coincidences.