Favorite scream in rock?

Lots of great ones mentioned. A couple of others

Geoff Tate - Queen of the Ryche

Ronnie James Dio - The last in line

"Nobody screams/sings like Eric Adams - no, not the NY Mayor..."

Not so fast, he may be screaming real soon...

Lead vocalist from Swedish progressive-metal band, Pain of Salvation, Daniel Gildenlow, has many great screams throughput the band's catalog, it's hard to narrow it to one. 

He also has amazing vocal chops overall. He has a 5 octave range, great intonation, ability to sing quiet in a pure voice, power to spare. 

At about the 4:27 mark on the song, "Used", is one example. 

At about the 3:40 mark of the song, "Handful of Nothing.

Another example is a live version of the song, "Hallelujah" at about the  7:40 mark. 

My Woman From Tokyo by Deep Purple

John Lennon on She wants you (she’s so heavy) on Abbey Road.