My parents were keen on detective fiction, so I got the bug at an early age. I enjoy this type of book to this day most especially when I simply want to relax rather than be desperately challenged by a book.
I must admit that I can rarely work out 'who done it' and if I do get it right it is due more to a hunch than a careful working through of the clues. I tend to enjoy this genre more for the characters and situations. I think whether you want to be 'be the detective' or simply enjoy other things about such books has a big effect on which authors you will enjoy, though of course many authors manage to cover both bases. Dorothy L Sayers I'd reckon was one of the latter and if you can put up with the ultra 'posh' background of the characters she's an extremely good writer.
P.D.James also wrote at a much higher standard than is found in your average 'whodunit' and is probably best known for her Adam Dalgliesh detective character has very interesting plots and characters but I've only got to enjoy her over the last year or so. When I was younger I found her writing very off-putting though I can't precisely say why. It is odd how your tastes can change over the years. Georges Simenon's detective character 'Maigret' is a classic of detective fiction and one I used to really enjoy but I now find the books quite distasteful though again I can't exactly explain why.
A big find for me were the books by Robert van Gulik which are set in ancient China so as well as crime and detection they provide the added interest of an insight into a culture massively different to our own. This quote is from Wikipedia:
Judge Dee (also, Judge Di) is a semi-fictional character based on the historical figure Di Renjie, county magistrate and statesman of the Tang court. The character appeared in the 18th-century Chinese detective and gong'an crime novel Di Gong An. After Robert van Gulik came across it in an antiquarian book store in Tokyo, he translated the novel into English and then used the style and characters to write his own original Judge Dee historical mystery stories. The series is set in Tang Dynasty China and deals with criminal cases solved by the upright and shrewd Judge Dee, who as county magistrate in the Chinese imperial legal system was both the investigating magistrate and judge.
As for The Cornish Coast Murder (1935) by John Bude (Ernest Elmore), this was actually a Book Club choice in early 2016 when we were still on The Fool and you can still see the discussion here:
http://boards.fool.co.uk/reading-review-thread-the-cornish-coast-murder-13320962.aspx?sort=whole#13320962