I have to recall now, I haven't watched them in a while. I like the venus flytrap one. I think that's the one where he had to cut the key out of his own eye in a certain amount of time.
Gotta go with the freezing/water one. It breaks away from the normal, neutral traps and adds an element to them. The element of water! It's not a device that gets ya, it's freezing water.
i was actually gonna vote for that one, but the venus flytrap stuck out in my mind. It was close between them, but I like the instantaneousness of the flytrap as opposed to the gradualness of the freezing water.