The autobiography of Giacomo Casanova is one of the wonders of world literature. The man had an incredible life, as a seducer, student, gambler, poet, novelist, spy, political exile, political prisoner, con-man, musician, librettist, and more.
His 12-volume memoirs have been brilliantly translated into English by Willard Trask, and are published by Johns Hopkins University Press. What's particularly nice about this edition, the covers of which all look much like this...
..is that the full set on the shelf look like this.
I think we can all agree that this is very nice.
A similar effect has been achieved by the current Vintage UK edition of Proust's À la recherche du temps perdu (which has a sketch of old Marcel himself spilling across all six spines) and the US editions of Anthony Powell's A Dance to the Music of Time, which has the painting of that name across all four spines. Unfortunately I have nothing to show you of these, image-wise. My Proust is made of from 3 different editions, and my Powell is the classic-looking white version put out by Arrow in the UK.
What I can show you are two other Casanova covers. The first is for his short novel, The Duel, from Hesperus Press. It's a great little book, and rather more manageable than his thousands-of-pages-long science-fiction epic, Icosaméron ou Histoire d'Edouard, et d'Elisabeth qui passèrent quatre vingts un ans chez les Mégamicres, habitans aborigènes du Protocosme dans l'intérieur de notre globe.
The second is from the lovely-looking Penguin Great Loves series. These books are gorgeous, though some of them are merely extracts from bigger works. The Casanova is a case in point, being a few episodes lifted from the autobiography.
UPDATE: I forgot to mention that the painting in question is Venus in Repose by 17th-Century Dutch artist Dirk de Quade van Ravesteyn. More information on the choice of this painting for the spines can be found here.