I hate both equally.
Wanda's insane genocide gets a pass because she was cray cray but her bitterly unrepentant attitude and feelings of victimization after and constant thoughts of saying 'No More Mutants'? Evil.
Medusa's cult leader posturing, putting the investigation of the Sky Spears above finding a way to save mutant lives, making sure no one could touch the sacred cloud[s] upon penalty of death, and just letting thousands of people (mutants and humans without enough Inhuman DNA) die horribly because it was politically and religiously expedient for her and her Inhumans? Evil.
Both are unrepentantly genocidal and would probably do the same thing again if given the chance. The only difference is that Wanda instigated her genocide while Medusa actively made sure hers was furthered after being started by Black Bolt.