"Engineers think that equations approximate the real world.
Scientists think that the real world approximates equations.
Mathematicians are unable to make the connection."
(stolen from nickys who stole it from a website somewhere)
Buffy: Nothing is simple any more. I'm constantly trying to figure it out -- who to love, who to hate, who to trust....
Giles: I believe it's called "growing up."
Buffy: I'd like to stop then, okay?
Giles [smiles]: Know what you mean.
[The vampire Buffy's been waiting for rises from its grave; she stakes it almost nonchalantly]
Buffy: Does it ever get easy?
Giles: You mean, life?
Buffy: Yeah. Does it get easy?
Giles: What do you want me to say?
Buffy: Lie to me.
Giles [as they begin walking out of the graveyard together]: Yes, it's terribly simple. The good guys are always stalwart and true, the bad guys are easily distinguished by their pointy horns or black hats, and, uh, we always defeat them and save the day. No one ever dies, and everybody lives happily ever after.
[fade to black; credits begin to roll]
Buffy [voice over]: Liar.
--Buffy The Vampire Slayer: "Lie to Me"
green_amber says this is the best quote from the entirety of Buffy and, personally, I can't think of a better one.