Opinions?

Like what would make him kill someone?

I'd say if someone killed Aunt May right before his eyes.

if one of his family members were killed (or worse) in front of him.

if he met joe quesada he would kill him

probably if a family member/friend was killed in front of him like the others said.

Spidey doesn't actually have a no-killing rule. He just does't like leaving piles of bodies all over the place.He's already killed Digger and Morlun, but I guess you could make the argument that they weren't human. He'll only kill enemies if he has no way to contain them and they're a huge threat. (Morlun was smashing up everything and was almost unstopabble, Digger was in Hulk territory when it came to power. You can read about them in the JMS run. Spidey Vol 2.)

Well he's killed a few people to be fair

He killed Dooms resistance fighters granted it was a complete accident that wasn't his fault (I mean seriously how the hell was he supposed to know those 2 guys were gonna drop through the same ceiling he was re-directing that rocket to)

Charle Magne deliberately set off his Spider-Sense so Peter was startled and knocked her the fuck out...of life.

He killed the guy who killed his parents (yeah Batman you wish had those balls)

He also attempted to kill Green Goblin many, MANY times.

Just shoot Aunt May like what the Kingpin did or threaten his loved ones

slap mary jane on the ass..then blow her up. that should do it. Or.,and this will probaly never happen,have twins with gwen stacy and order them to kill peter, that should make him mad. But alas...what are the chances?

What do you think would break Spidey's no killing rule?

A face to face meeting with Dan Slott;)

I have to agree if anything drives Spidey to the point of psychotic rage it's threatening those he cares for.