LAWFUL GOOD: "We're gonna bust this thing wide open, and then do the necessary paperwork" (Nicholas Angel & Danny Butterman from Hot Fuzz)
NEUTRAL GOOD: "It's easy to forget what a sin is in the middle of a battle field" (Solid Snake from Metal Gear Solid)
CHAOTIC GOOD: "Governments should be afraid of their people" (V from V for Vendetta)
LAWFUL NEUTRAL: "I used to study people... but I think I got bored." (Gil Grissom from CSI)
TRUE NEUTRAL: "Whatever works." (Machiavelli from The Prince)
CHAOTIC NEUTRAL: "Might save your life, might steal your car." (Matt from Death Note)
LAWFUL EVIL: "Bringing order to the universe...even if we have to choke the shit out of it." (Darth Vader from Star Wars)
NEUTRAL EVIL: "I will cease to exist as I am now...only to be reborn as a god to rule over every soul." (Sephiroth from Final Fantasy VII)
CHAOTIC EVIL: "Real horrorshow." (Alex from A Clockwork Orange)
[Addendum: Missing descriptions courtesy of HWMNBN]