Eli Bendersky's website Audiobook (from librivox.org)
The quality of reading in this book was pretty good - at least there were no unintelligible readers. I'm now downloading only the 64kbps recordings as they're more than enough for speech.
"The memoirs" is a collection of 12 short stories, in the last of which Holmes meets his arch-rival Prof. Moriarty and allegedly falls to his death (together with Moriarty) from a narrow path in the Swiss mountains. Worry not, Holmes comes back for more stories later - but Conan Doyle took 7 years between publishing this book and the next one, which leads one to think that he may have really intended to finish the series. It's a bit like the situation with modern movies which insist on trilogies. The difference is that Conan Doyle's later stories are as good as the early ones, which isn't the case for the movies. But I digress.
Anyway, "the memoirs" is as highly recommended as the other stories about Holmes, and while I'm writing this I'm already downloading the next book from librivox.