It's barely funny in its own right, but with the build-up I think it's one of the best scenes in the canon.
Death, you know, SPEAKS LIKE THIS, has decided to woo Renata in Reaper Man and has bought flowers and a box of chocolate probably big enough to surf on, but with totally black lid apart from a kitten. Or similar. And now he's in the jewellers, having been given the advice that diamonds are a girl's best friend. The problem for the jeweller, of course, is that whilst he is right up with it if asked about colour, timbre, sparkle, clarity and carats (note spelling, this is not an overly high dwarf who is definitely not the missing true king of Ankh), he is considerably less comfortable when asked about a jewel's friendliness. However, when the chase is cut by the skeletal one, he finds his understanding warming up to the concept.
(quoting from memory)
AND WHAT IS THE LARGEST DIAMOND ON THE DISC?
That would be the "Tear of Offler", the altar piece in the hidden Temple to Offler, deep in the jungles of Ee. And, sir, to forestall your next question, personally I'd go to bed with it!