I think a behind-the-scenes book about the history of the Mosconi Cup would be really interesting...
How the players are selected, the different changes the format has had over the years, Matchroom's involvement...
As for player biographies, there is one that stands head and shoulders above the rest... And this is really something for JAM to do or be directly involved in...
Keith McCready...
I will guarantee that a biography of Keith that is done right and professionally will sell better and bring more attention to pool than almost any other book has...
But again, JAM has talked about doing this and it really is her project...
And to second a vote from a previous poster, a biography about UJ Puckett would be tremendous... Especially in an oral history format where various people who knew and played UJ are interviewed...