Mine would be
1.) The Godfather
2.) The Fortunate Pilgrim
3.) Fools Die
4.) Omerta
5.) The Last Don

I've yet to read The Fourth K and the Sicilian and I just started the Dark Arena.
The Family isn't going to be published in Australia at all which I'm not happy about. So if the guy who posted an answer to my Family in Australia question reads this thread, there's some bad news for you. I really really hope I got the wrong information though.
Liz.