Doreen Court's latest edition of her weighty tome on the succulents of Southern Africa is quite amazing. Published in 2010, it's very up-to-date with the newest taxonomic changes and species listings for hundreds of succulents, including the entire bunch from Mesembryanthemaceae (say it 10 times fast).
Doreen Court sounds like an amazing person. She was born in the Little Karoo, and now lives in the Western Cape. A Fellow of the Linnean Society, Court's knowledge of these plants seems quite inexhaustable! And her enthusiasm for the subject seems quite unquenchable.
The photography is excellent; there are hundreds of dramatic closeups in full color. Most of the plants are shown in situ, which makes it particularly interesting for gardeners who usually see these plants only in collections (in my case, that means in small ceramic pots). It's available on Amazon now for around $30(US) in a beautiful hardcover edition. I've also seen a few copies on the 'bay and with online booksellers.
The only difficult aspect of the book is that the written entries on each plant are not next to the photographs. In other words, there's a large text section followed by pages of photographs, so you have to flip the pages back and forth as you read. Picture, text, picture, text. Once I got used to doing that, it was pretty easy to use. All in all, it's a very necessary, and enjoyable book for people who grow and collect succulents, and particularly, mesembs.