I picked "he licked my face.." because Syd doesn't get enough comedic moments like those. She gets to be dramatic and cute and kick-ass all the time, but she rarely gets to be funny, so those one-liners really stand out when they occur.
I voted for: "You get to tell your friends that you work for the CIA while I go home and look desperately for a tiny moment that I can be honest with anyone about anything. Now that Will knows the truth... he's never going to trust me again. You should have seen his face in Paris. It was like he was looking at a stranger." That's just a powerful statement about her line of work. Although, I love every line she says.
I just thought of another Sydney quote that I love that wasn't listed. It was the one to Vaughn, "Yeah, could you show me what a paper bag looks like again?" I just love sarcastic Syd.....I made use of this today when my mom showed me how to put the tree ornaments in ziplock bags, then asked if I needed help, and I said, "Yeah, could you show me how to use a ziplock bag again?" She just gave me a mean look and left the room.