I love Endless Night and was so happy to hear there was a movie. Then I learned the casting and thought, "Ugh. The only one cast right is Britt Eckland." Lol, I watched it and it turned out that BE was the only actor I didn't like! I'd like to see it re-made with Colin Farrell, Anne Hathaway, and Scarlett Johansson -- and more emphasis on the spookiness.
As to Tommy and Tuppence, I have just not been able to get into them. Especially Postern of Fate. I've tried to read it twice and I just can't finish it. (For me, there's so much blabbing in Tuppence's head, I get bored).
My favorites are "The Seven Dials Mystery", "The Secret of Chimneys", and "Easy to Kill." I like the ones in which the murderer is the least expected but always present character, who suddenly turns at the end!