Take two, I guess.
I do agree that it's pretty hard to top the villains I've listed. But the whole point I was making was that asking for every villain to be redeemed is gross and extremely naive. And in terms of MLP, Chrysalis, Cozy Glow, and Tirek are just plain evil.
Chrysalis effectively drained the love out of ponies even when there were other ways for changelings to survive, Cozy Glow manipulated multiple ponies (even the princesses) for her own gain, and Tirek's whole shtick was draining others of their magic.
And yes, whether you like it or not, they were indeed given chances to change, but they always shot it down.
But to be honest, I feel that you'll just ignore my points and jusgo right backee to ranting.