I love detective stories and over my reading life have certainly accounted for quite a few. When I was about twelve I remember reading Ten Little Indians (though it was then called by its much more politically incorrect title) and was totally floored by the denounment which I will not mention just in case there is anyone left in the world who has not read this particular Agatha Christie.
After reading every single book of Mrs Christie that I could lay my hands on I then discovered Ngaio Marsh and her simply gorgous detective Roderick Alleyn. Tall, elegant, aristocratic, sensitive, intelligent - what more could one want in a hero? He has a bumbling MP brother George, a glamorous mother and is married to a painter Agatha Troy, not quite a self portrait of Ngaio Marsh, but based on her experiences as an artist. Roderick Alleyn has the obligatory plod as his side kick, in this case, Detective Sargeant Fox who Alleyn rather whimsically calls Brer Fox. Ngaio Marsh obviously adores her detective but can occasionally tip over the edge and become rather 'precious' in her portrayal, particularly with her characterisation of humble and loyal servants in the upper class houses that Alleyn frequents. In her books the working classes don't quite say 'Cor blimey, guv, you're a real toff' but it is a close run thing.
Her books are beautifully written and quite a few of them have theatrical settings. Dame Ngaio, as she became, more or less single handedly introduced her home country, New Zealand, to William 
Shakespeare and formed her own touring company which toured both North and South Islands bringing Shakespeare to the most far flung places. One of her earlier novels, Vintage Murder, is set against such a background. Others with a theatrical setting are Overture to Death, Opening Night and Death at the Dolphin.
Her powers never waned as she grew older, unlike the aforementioned Dame Agatha, whose later books were somewhat rambling, and she retained her style and sharpness to the end. Dame Ngaio, who recieved her Damehood for her services to the theatre, wrote some 30+ books, and there is not a dud among them. Her writing spanned the 1920s up to the 1960s and she remained a best seller all her life.
Detectives have usually been served well in TV adaptations, Lord Peter Wimsey, Hercule Poirot and Miss Marple being fine examples, but sadly the Alleyn Mystery series made in the 90s, while demonstrating wonderful production values, was singularly lacking in characterisation. A grave disappointment so I just return to the books over and over again which never let me down.
