This fits the part of my listening project which can generally be classified as 'The 15 years or so when Bethan fell of the popular music radar [not that she was ever much on it...]'.
I've never heard Back to Black. I've heard 'Rehab'. I've conducted Rehab a couple of times. And that's about it. So, time to catch up, so I don't have to pretend to nod knowingly when it's next mentioned.