Though a bit old fashioned (it was written in 1960) and full of generalisations about the character of the Venetian (which is one of the reasons it seems old fashioned) it is still in this 1993 revision an excellent and enjoyable read. The foreword to this edition, in which the author justifies not making many changes, is a delightful read in itself.
To be read slowly, and savoured.
Some others I have are in this post.