I think this part means "Nothing":
What do men love more than life? Nothing.
What do men fear more than death? Nothing.
What do dead men have and rich require? Nothing.
What do contented men desire? Nothing.
If i'm right, assuming that the creepy voice is Samantha's, she is dead.
And before you say "Everyone knew she was dead", look this page (CoD Wiki):
http://callofduty.wikia.com/wiki/Hellhound
Copied from the page:
"In hellrounds, if you listen closely you can hear whispering voices in the background. Confirmed in Black Ops.
It sounds like the voice might whisper "The girl is alive" which may mean Samantha is possibly still alive."
