What she did was straight-up evil.

Scar killed his Brother. Tried to kill his Nephew. Took over Pride Rock. Tortured Zazu. Was being Sexist to the lioness's. Starved everyone but himself. Fought his Nephew to the death. (PLUS HE IS BEAUTIFUL)
Whats not to love to hate about him!?!

^hHutchy, I couldn't have said it better myself.

As for the others, I like The Queen, Captain Hook, Shere Khan, Madame Medusa, Sykes, Ursula, Jafar, Hades, John Silver, Bowler Hat Guy, Gothel, Kaa, the Hyenas, Randall, and Lotso.

Frollo was prejudice against anyone who didn't conform to his views on things, he was a hypocrite, raised a child whose mother he killed and made him think that he was worthless, ugly, a monster and stupid, imprisoned tons of people, and finally he uses everyone for his own advantage. Also, he sang the darkest Disney song ever.
He def has my vote for the baddest Disney villain.

Yeahh Frollo is a BADDD man

And Ronno <3

She is a BAMF.