As we read different comics/books and watch TV shows/movies, there are villains whom you can love and hate depending on how they are written, the concept, their personality or their deeds.
So in this case, what kind of villains do you hate so much that you want him/her to be killed off or never see him/her again.
For me, I hate villains who are rapists (e.g. Purple Man), torture-and-kill animals (e.g. Brix and Bora of the Inheritors) and poorly-written villains in general.
MY MOST HATED VILLAINS I DESPISED SO MUCH
- Purple Man (with the combination of mind control powers and slimy personality, he is quite a creep for raping the women and forcing Jessica Jones to watch)
- Mandrill (the pheromone powers are creepy and also he has women as his slaves to be used as soldiers, harem or whatever. And he looks like a monkey)
- Daemos of the Inheritors (other than killing Mayday's father, he sexually harassed Lady Spider and he hurt the New Warriors just to get Kaine)
- the S.H.I.E.L.D scientists who experimented on Niels the Bouncing cat (not only that they threatened to put the cat down, they also call it 'Not human' in front of Jim Hammond who is an android)
- the Hellfire Brats (poorly-written kids who replaced Sebastian Shaw and none of them are threatening)
- Vulcan (he's poorly conceived, ridiculously powerful and he has a personality of an overgrown toddler in an adult body),
- Brix and Bora (other than killing any versions of Spider-Man/Spider-Woman they come across, they tortured and killed Spider-Kitty)
- Cassandra Nova (poorly conceived and she commits genocide on Genosha for fun just to spite Xavier)
- Lash (a bad replacement for the charismatic Magneto or Exodus who kills any Inhuman follower who annoys him in a petty way and he is very bland for an extremist Inhuman leader)
- Reverend Stryker and the Purifiers (other than being cowardly for blowing up a schoolbus of depowered mutant kids and slaughtering the innocent civilians and babies of Cooperstown in Alaska just for the mutant baby, they also give a bad name to Christians)