I cannot recommend reading the complete works of P.D. James (less two books the library didn't have) in a fortnight. One comes to notice certain repetitions and obsessions (what is it about modern bacon?) and also to dislike Adam Dalgliesh, her far-too-perfect detective.
James has one really good trick, which is to make the victim someone so eminently dislikable that you'd kill them yourself. In Death in Holy Orders I found myself muttering "Oh good!" when I came to a chapter entitled "Death of an Archdeacon". Sometimes the murderer's reasons, when revealed are implausible, but the person was usually so horrible you're just relieved someone got rid of them already.
Once or twice James cheats, with "Of course, it had been obvious all along to Almighty Adorable Adam Dalgliesh, the poet detective, that the harmless inoffensive X was the most likely suspect..." while not having had this be the slightest bit obvious to the reader. This is done to disguise Dalgliesh's stupidity, without which there would be no plot. But apart from that, they play pretty fair with the reader.
On the whole these are pretty decent cosies, and would probably have benefitted from having been read at a more sane pace.