-- Decapitation.
-- Freeze them and then knock them down so their body shatters.
-- Squeeze their head in so their brain is squished and blood seeps through their eyes.
-- Stab them through the neck.
-- Shoot them in the head, eye, mouth.
-- Best way to make sure they're dead: Blow them up, chop them up and gather the pieces and burn them.
Sorry if this is out of place, I just watched Resurrection so I'm kinda in that... mood...or state of mind...whatever.