This might surprise some people, but my favourite on this album is She is My Sin. I don't think any of the other songs on the album speak to me as much as this does, not even the very beautiful Dead Boy's Poem. The heavy version of Sleepwalker might come closest, and as a treat I decided to link to that song too. It's so much better than the normal version, at least!
I don't really know what it is in She is My Sin that enchants me so much. Maybe the very down-to-earth lyrics with the catchy riff, and the piercing high notes that once was my goal to be able to sing without wavering (made it, booyah!).