dev·il's advocate
n.
One who argues against a cause or position, not as a committed opponent but simply for the sake of argument or to determine the validity of the cause or position.

A pick me is a woman that is willing to do anything for male approval. She will embarrass or throw other women under the bus to achieve this goal. The unfortunate thing about a pick me is usually the men they are trying to seek approval from are of poor quality and treat women badly, leaving little real benefit for the pick me.

One who argues against a popular cause or position, not as a committed opponent but simply to make people discuss and consider it in more detail.

to argue just for the fuck of it.

One who takes up the opposite argument to another person's statement or position, just to cause a problem for them.

This awesome movie where Al Pacino plays the Devil and owns everybody in New York City, but more importantly is taking his gangster roles in Scarface and The Godfather to a greater level of sophistication.

someone who chooses to say the opposite of what another person thinks or says, simply to be an asshole.