I’ll go first. Mine is the instant knockout drug. Like Dexter’s intramuscular injection that causes someone to immediately lose consciousness. Or in the movie Split where there’s the aerosol spray in your face that makes you instantly unconscious. Or pretty much any time someone uses chloroform.
IIRC, neither was wearing armor in the book, but it’s been a while so I may be wrong.
And the book at least talks about aiming for the gaps in the armor.