there is so many good suggestions here - thank you all...
I have one too, something I've just read.
The title is:
Fool's Paradise - D. L. Zane
This is a story about a love between a woman, Lady Jade Northwick, and a devil, Lucian Drake, Count of Darkwood.
Lady Jade Northwick is a distinguished member of high society and a hopeless romantic who dreams of meeting her Prince Charming.
She encounters the striking Count Darkwood at a palace ball and learns of his bad reputation; nevertheless, the mystery surrounding him starts to intrigue her.
When she learns that her father has gambled away their money and agreed to marry her off to a man she despises, in order to help repay his debt, she is devastated and decides to seek help from Darkwood. Soon, however, Jade finds out that she is asking for a favour from the devil himself.
Lucian’s main purpose of existence is taking humans souls, but a series of events that will follow after he makes a deal with Jade’s father, will forever change his life. And for the first time in history, one devil will fight for salvation of a human soul.
I absolutely LOVED it and had to share You can find it on Amazon kindle (free at the moment)