Garak is also my favorite DS9 character. I wish he had been made part of the main cast.
Anywho here are some of my faves.
Ziyal: You're intelligent and cultured...and kind.
Garak: My dear, you're young, so I realize that you're a poor judge of character.
Odo: I think you secretly enjoyed destroying your own shop.
Garak: Well, I admit watching it burn wasn't exactly tragic.
Bashir: Assuming you're not a spy...
Bashir: ...then maybe you're an outcast.
Garak: Or maybe I'm an outcast spy.
Bashir: How could you be both?
Garak: I never said I was either.
Garak: Well, it's just that... Lately I've noticed everyone seems to trust me. It's quite unnerving, I'm still trying to get used to it. Next thing I know, people are going to be inviting me to their homes for dinner.
O'Brien: Well, if it makes you feel any better, I promise I will never have you over.
Gul Toran: It's Gul Toran now.
Garak: They made you a Gul? I didn't realize the situation on Cardassia had gotten so desperate.
And of course this scene which was already said, but it's my favorite~~~!!!!
Bashir: What I want to know is, out of all the stories you told me which ones were true and which ones weren't?
Garak: My dear doctor...they're all true.
Bashir: Even the lies?