Just after the crash, Ottway finds one of the survivors screaming about how much pain he's in. Ottway says it's good that it hurts (it means he's neither paralysed nor in shock,) and the man gibbers "if it's good then I'm fucking fantastic!"
Pretty much anything that comes out of Flannery's mouth, especially his "wolf-man" comment.
"I didn't say it was my best plan."
Diaz flipping out after the Omega almost kills him. The others just look at him continue to stab the corpse and Ottway eventually say "I think you got him". Diaz ignores him and keeps stabbing.
Ottway: That's an Omega, an outcast... They sent him here to test you, Diaz.