I consider my books to be contemporary romantic suspense because I like to write my characters into scary situations.
I don't always want them to come to physical harm, but I do like to get their heart rates beating out of control.
They should experience some real fear.
Fear of what's behind the curtain.
Fear of what will happen next or what won't.
Fear of losing their life or the life of someone else.
Without those real feelings of fear, the characters can't always appreciate what they have or what they want.
Plus, I enjoy torturing them and my readers. :)