5. The Black Album - It's not a thrash metal album -- Sure it's not the Metallica we all know and love, but it's still good music
Love is obviously more debatable here... but given the commercial success and very extensive airplay lots of their 90's work got and do this very day, I would argue it's definitely the Metallica we know... Or perhaps, in this case, the Metallica they know, if we want to embrace the Metal Community - how ever one defines it.
As for love, I have to admit that a good number of my favourite Metallica songs are from the 90's and onwards but I definitely do not deny the outrageous power of their older records, or the supreme quality of records like Master of the Puppets or Ride the Lightning. As far as their albums go, they haven't released anything as tight and powerful since, as much as I love many individual songs from their later works anyway.