Your personal opinion. There's no right or wrong answer
Basically, the trap that made you look away, made you nauseous, or made you scream, or just had an effect on you because of personal reasons. For me that trap is the needle pit, for a few reasons
I have trypanophobia (The fear of needles. Most people are scared of needles as kids but it's an actual phobia)
At the time I first watched Saw 2, for the sake of not revealing anything too personal about my cousin, let's just say their life wasn't going very well
Those close up shots of the needles show us that they're crusty and covered in who knows what kind of diseases and shit