For me personally , Pyromania is the ultimate. It is by far my fav Def Leppard album. it had it all , it rocked hard so appealed to hard rock/metal fans of that time, Joes voice was at his best where he coudl do the high screams, and deliever clear but rough sounding vocals, yet it was very melodic and chorus to appeal to those who like more of a pop feel.

The album also really change the direction of hard rock and opened up the record companies to sign and push bands similiar to def lep sound.

While no one can argue how good Hysteria was and how it also changed the direction and sound of the time, I still much prefer pyromania and wish def lep would ahve stayed to a slightly harder edge to them.

sadly they never go back to that more agressive yet melodic sound.