Dear Diary
I'm a sucker for diaries. Even boring ones, I like to at least sample. Parson Woodforde, who loves to report on what he ate for dinner - I don't mind, I want to know what he ate for dinner.
Fanny Kemble, George Templeton Strong, Frances Partridge, Virginia Woolf, Kafka, Thoreau, Boswell (dear Bozzie, what a joy he is), Marie Bashkirtseff, Dorothy Wordsworth, Emerson, Dostoevsky, Katherine Mansfield. I eat them up.
The only one I can think of I don't like is Sylvia Plath's. Partly because I hate the ridiculous cult about her, which wouldn't exist if she hadn't killed herself, and what kind of stupid reason is that to make a hero of someone? but much more because of the content. The soppiness, the sub-Lawrentian guff about Ted and babies, the bad literary taste.
Susan Hill has a very good article here about diaries. Kilvert, Pepys, Scott, Sarton (that's another I don't like much), James Lees-Milne.