She grew up in a house which was the end of our road (long gone sadly) and Torquay features a lot in her novels (one of the houses on the next road down features in one of the novels too).
At Bertram's Hotel did it for me - it may not be the best of her whodunnits, but as a youngster, I was really taken with the setting of the hotel itself.
@Cristobal I have read quite a few of her books and can say I loved Man in the Brown Suit. I have The Secret Adversary downloaded on my IPad but have not gotten to read it yet. Will make time soon. Also loved And Then There Were None.