It is estimated that the best-selling album of all time in Italy is La vita è adesso (1985) by Claudio Baglioni which remained for 27 consecutive weeks in first place in Superclassifica "TV Sorrisi e Canzoni", from 16 June 1985 to 12 January 1986 (a record that still stands today) and a total of 90 weeks (18 months) in the top ten with more than 3,800,000 copies sold.
The best-selling Italian album in the world is Romanza by Andrea Bocelli, with estimated 20 million copies (1,100,000 in Italy).
The best selling foreign album in Italy is estimated to be True Blue by Madonna with 1.4–1.5 million copies.
Best-selling albums of all-time in Italy
These are the top 10 best-selling albums in Italy according to sales by SIAE.
References
List of best-selling albums in Italy Wikipedia(Text) CC BY-SA