Iron Maiden - Hallowed Be Thy Name is what I consider quintessential Maiden. Everything from Harris’ bass to Dickinson’s incredible vocals.

While I was initially going to put Black Sabbath (the song) here as well, I think War Pigs is far better option.

The composition, the lyrics, Ozzy’s voice, and every instrument feeling distinct and getting its own little bit of spotlight. It’s just a fantastic song in so many respects.

There are a few others, but I’m just sticking with those two for now.