My most recent purchase of book porn is Faber and Faber: Eighty Years of Book Cover Design (which I first mentioned here).
This is a lovely, oversized (roughly A4) collection of images of Faber's covers from 1929 onwards. The text is minimal, but there are hundreds and hundreds of pretty pictures to look at. Excuse the photographs (which you can click for much bigger views), but there was no way I was killing this thing's spine with my scanner.
The book itself had its cover designed by Neil Gower, mimicking the classic work of Berthold Wolpe, who did pretty much all of Faber's covers for some 35 years (as well as designing Albertus, the font used on this and many other earlier Faber covers).
Faber, at least in its earlier decades, did not have the range of cover art of, say, Penguin, due in part to having one designer with a consistent vision, but there are plenty of gems here.
My only criticism is that Connolly seems to lose interest after about 1980, and there are hardly any covers from the last 30 years shown here. This means that there are few of Pentagram's covers, and, weirdly, absolutely none by Andrzej Klimowski. It was Klimowski's covers for the work of Milan Kundera that first caught my eye and drew my attention to Faber back in the late 1980s/early 1990s, when I was a young lad for whom the combination of literature and naked women was pretty much irresistable.
(For Klimowski doing Wodehouse, see here.)