Which Metallica album sold the most?

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Tags

1. #metallica
2. #panel
3. #albums
4. #master
5. #since
6. #longest
7. #album
8. #country
9. #soundscan
10. #selling
11. #studio
12. #successful
13. #puppets
14. #years
15. #sales
16. #months
17. #consecutive
18. #highest