My all-time favourite line was definitely when someone said about me: "Why can't HE just be GAY like NORMAL people?"
My friend was having an arguement with this person about transpeople, and this was his great conclusion of the situation.
I was also once at a meeting with a small political group in Iceland where I and one other transwoman were discussing the legistration of transgender rights in Iceland, and after we had been discussing the matter for a while, one of the guys stands up and says:
"Well, you are a very convincing woman."
Which I of course explained to him that I wasn't trying to be a woman, I had always been one, and this was not just some role I was trying to play. And then a while later he asked: "Is this your female voice?" to which I promptly replied: "Well, yes, I got it in the woman's section at the store. " even though I knew what he meant by that.
He pretty much looked pretty stupid infront of everyone. Which I found a bit amusing.