Ah, that would be Comatose by Skillet, Slipknot by Slipknot, Sehnsucht by Rammstein, and Scary Monsters and Nice Sprites EP by Skrillex.
Each introduced me to a new kind of music, and/or furthered my taste in music.
Comatose was the one that started me on music in general. I heard one of its songs, "Whispers in the Dark," in a fan video telling the love story of male Revan and Bastila from Star Wars KotOR, and borrowed the album from a friend. That's what started it all for me.