I saw Saw 1, 2, and 3, and decided after 3 that I needed a break from the hilarity. That scene in Saw 3 where the dude is clamped in to that vise-like device that cranks his body parts 720 degrees - I mean, look, in any sort of reality that would be pretty messed up but I couldn't help but laugh my ass off at it in the movie. Saw 3 was SO over the top - I can only imagine the subsequent sequels amp it up more and more.
But don't get me wrong - I love that these kinds of movies still get made. 5 Saw movies now? That's great, seriously... I thought the endless-sequel thing was sort of over, they got Freddy Krueger and Jason together in a movie and it was like the film industry acknowledged there is only so much you can do with the same bad guy, even if there's 2 of them in one flick. Which is tragic, really. Trashy cinema definitely has its place. You can crank these things out cheap and they're entertaining enough to keep people coming back, more power to you, I say.