A way of saying "I don't care what you're saying but I'm gonna go ahead and say I liked the story."

Usually used after listening to a long story or gossip.

Phrase used sarcastically to express a lack of interest in what the other person is saying. Often written on the Internet as, "cool story bro".

A response to a story or piece of information that you find boring, or is too long and you don't want to read it.
One extra note, though. The only proper use of "Cool story, bro" is to say it exactly as it is in the quotes. Any other variation ("Interesting tale, brethren", "Wonderful retelling, sibling") should never be used under any circumstances, and will make you look like a complete failure to everyone who reads it.

What a douchebag says when (s)he wants to completely disregard a separate party's important and/or drawn-out speech. Contains a similar connotation to "tl;dr" but with an elevated amount of douchefaggottry.

A catchphrase used when a person says something complETEly unrelated to the topic you were just talking about.