I loved this bit of dialogue here where the protagonist, Richard Mayhew, runs into his former fiancée.
“Would you think,” Richard asked, “that I was being picky if I pointed out that trying to find something with an angel on it in here is going to be trying to find a needle in an oh my God it’s Jessica.”
The fun part of course is that this is how people really talk when they’re surprised. I also noticed that the delivery of the dialogue is some much more effective without the use of ellipsis, which is how I would have been inclined to write the sentence. This joke also works because the reader fills in "haystack" mentally before the reader even gets to the actual words. Hence, the surprise.