To express a great anger especially when you find the statue of liberties arm and torch half buried in a desert in the future where the planet is ruled by apes.
Planet of the apes : "We finally really did it. You maniacs! You blew it up! Damn you. God damn you all to hell."
What you say when "God damn it" just doesn't suffice-- you need to damn it even harder. First used by Vegeta in Team Four Star's Dragon Ball Z Abridged, it has come to be commonly used to express one's inner torment.
Stronger than damn, stronger than god damn, and yes, even more powerful than god damn fucking, god damn motherfucking is for when you really god damn motherfucking mean it.
well,it's like an expression someone speaks it when they are amazed at something (explosion/knock-out/big house on fire,etc).
the example will explain better go to youtube and write god damn what a rush,the video length is 11 seconds.John Travolta says it there
John Travolta says in amazement (when he saw a big nuclear explosion):God damn what a rush.
he was a bad guy and he liked the explosion
Ross: Hey you guys makin' a commercial?
Danny: That is a sweet shirt Ross, but it isn't gonna make our dinner any faster, that is a sweet shirt.
Ross: Oh. Okay.
Arin: *whispers* God damn it Ross...