I followed Def Leppard from their beginning (on Radio), but Pyromania was the first LP I could put my hands on. I bought it in Sweden visiting my grandparents and took it back home, where it wasn't available yet. I was KING... for a while anyway. Also, I like every song on it. Moreso, it was the album that made me aware of Mutt Lange and his wizardry behind the glass. With Euphoria on the way, Def Leppard had an impressive climb over 4 consecutive releases.
On another note. Being a parent myself perhaps I can provide you with insight for why your folk's felt it was OK to buy you Pyromania, but not Stay Hungry and Hi-Infidelity. You see, parents... they know their kids. So if there is no danger of them burning down a building, you buy your kid the Pyromania. Following the same logic... If the same kid has tendencies to dress in drag, and God forbid harbor pervy thoughts... Then... You don't want to add fuel to the fire (no pun intended).
Low hanging fruit.
Funny man! :D