I like heavy texts but something exciting, yet historically accurate obviously, would be preferred!
A couple from the history of culture angle:
F. W. Kent, Lorenzo de' Medici and the Art of Magnificence
Konrad Eisenbichler, ed. The Cultural Politics of Grand Duke Cosimo I de' Medici.
Two books I can recommend:
Lucrezia Borgia: Life, Love, and Death in Renaissance Italy by Sarah Bradford.
Murder of a Medici Princess by Caroline P. Murphy.