Top Ten Songs to Compare Which One is Heavier

To me Pleasure to Kill.

I think it's quite obvious.

Master of Puppets sounds heavier to me

To me Master of Puppets.

Hmm this one is tough, but Stone Cold Crazy has more aggressive vocals and heavier solo so I'm going with Stone Cold Crazy.

Both of them have different tempos. The intro of Speed King which was played by whammy bar, is very heavy. Cause it made a very low pitched sound. But Black Sabbath had more low pitched riff. But I'll go with Speed King. If not anything then only for the whammy intro.

For me Speed King is heavier because it has more extreme elements - it's faster, louder and has more aggressive instrumentation and more aggressive vocals. Speed and aggression are key elements of extreme music (metal, hardcore punk, etc.).
You can check out Venom's cover to hear the full potential of Speed King.
Also check out the list Top 10 Characteristics of Extreme Metal

To me Speed King. Same as Helter Skelter vs I Want You.

To me Helter Skelter, speed is heavier than doom to me.

I know people who mostly into more distorted riffs and doomy songs would say Iron Man, but to me Kick Out the Jams won this competition.

For me Kick Out the Jams is heavier.

Arise. Maybe You Will Know My Name has growl vocals, but it's cheesy a bit, while Arise is not.

Agree with this one, too: Jesus Christ Pose is heavier