For those who haven't played Planescape: Torment (spick please abstain <img src="/ubbthreads/images/graemlins/winkwink.gif" alt="" /> ), here's a nice one:

"Think of words that end in -GRY. Angry and hungry are two of them. There are three words in the common tongue. Which one is the third word? If thou hast listened carefully, I have already told thee what it is."