The first one had way better and more original traps than the other two.
Saw:
Cutting off your own foot to escape, and the fact that they actually showed the whole thing. That was awesome.
The reverse beartrap was probably the most original way to kill someone ever conceived. I suspect they had to make the chick survive because it would be way too much showing her head getting ripped apart. Plus she had to stab her way through someone else.
The razorwire was meh, seemed a bit corny that he would be TRAPPED FOREVER but it related to his whole cutting himself.
The guy who gets incinerated, that was cool.
Saw 2:
The Iron Maiden was a ripoff of the reverse beartrap, and having to cut your own eye out is a ripoff of having to cut your own foot off.
The gun through the peephole was crap.
The furnace was a ripoff of the incinerated guy.
The needles were cool.
The chinese handtrap thing was sort of cool.
The electrified cage thing was crap.
The nerve gas was crap.
The crazy convict guy was crap.
Saw 3:
The body chain was cool.
The ribcage thing was cool.
The ice water was crap.
The pig guts were crap.
The body twisting thing was probably the only really good thing in the movie that rivaled the first movie. However, the whole shotgun part that killed the judge pretty much ruined it.
The shotgun collar was a ripoff of the peephole gun.
Jigsaw getting sliced up by a buzzsaw was also fairly cool.
Detective matthews bashing his foot until it came out of the chain was pretty cool.
Adam getting suffocated was crappy
Point being, nothing rivaled the feeling you get in the first movie when Dr. Gordon goes insane when he can't reached the phone and starts cutting off his foot. That entire end sequence was done so well, with Zep getting bashed about 30 times with the toilet lid. The reverse beartrap was the coolest thing ever though