I use to have an add-on back in wrath that had every boss quote in the game, along with ways to macro them and my favorite, a random button that would play a random quote. After a bit of searching I found the add-on, but it hasn't been updated since 2009.
http://www.wowinterface.com/download...sBossTalk.html
edit: I found an updated add-on by brellison94
http://www.wowinterface.com/download...ellison94.html