I'd give it all up for her....
v. 1. (in sports) A sudden action - usually the result of a successful plan - that changes the entire course of a game or match.
Emma Stone's character in "Crazy, Stupid Love," whom Ryan Gosling's character considered a Game Changer.
Belldandy from the anime "Ah! My Goddess"
Lisa Leveridge as described in "The Game" by Neil Strauss
Every Michael Jordan moment in the NBA play-offs
Marshawn Lynch's run against the New Orleans Saints in the 2011 NFC Wild Card game
Jon Jones' successful counter-punch on Lyoto Machida
The most effective gamechangers are those which cannot be predicted using the clues introduced to the narrative so far, and leave the audience completely and utterly confused.
A gamechanger can, in the minds of some fans stray extremely close to Jumping the Shark, however a gamechanger is often seen as a positive if it enhances the quality or intrigue in a work of fiction.
Words also commonly associated with a gamechanger when they are shown, are WTF and OMG and Holy Shit.
"That was SUCH a gamechanger when Neo woke up in the real world man, didn't see that coming. That was fucking awesome"
"I'm fucking sick and tired of Lost nerds on the forums telling me that there's going to be a gamechanger in next week's episode"