Suggestions by @pichloza

Michael James Shaw

as Corvus Glaive in Thanos

Score: +1

Carrie Coon

as Proxima Midnight in Thanos

Score: +1

Tom Vaughan-Lawlor

as Ebony Maw in Thanos

Score: +1

Josh Brolin

as Thanos in Thanos

Score: +1

Hans Zimmer

as Composer in Namor Sub-Mariner

Score: +2

Ron Perlman

as Best Marvel in Best & Worst Comic Book Castings

Score: +19

Patrick Stewart

as Best Marvel in Best & Worst Comic Book Castings

Score: +164

Elizabeth Olsen

as Scarlet Witch in X-Men Reboot

Score: +9

Halle Berry

as Storm in X-Men Reboot

Score: -13

James McAvoy

as Professor X in X-Men Reboot

Score: -1

Michael Fassbender

as Magneto in X-Men Reboot

Score: -8

Seth Rogen

as Ben Grimm in Namor Sub-Mariner

Score: -1

Emily Blunt

as Susan Storm in Namor Sub-Mariner

Score: +2

John Krasinski

as Reed Richards in Namor Sub-Mariner

Score: +3

Emily Blunt

as Invisible Woman in Namor Sub-Mariner

Score: +1

Emily Browning

as Invisible Woman in Namor Sub-Mariner

Score: +1

Zachary Quinto

as Namor in Namor Sub-Mariner

Score: -5