My favorite is Bog king from Strange Magic - Has a song talking about how evil he is. But all he does is prevent the spread of dangerous mind control magic, and quarantine people under the effects of said magic. Yes he greatly annoys people doing so, but honestly? If I get hit by a love potion, please quarantine me.
Character that insist is evil but clearly isn’t: Crowley from Supernatural.
But I think that character that is actually evil but still charming is more interesting, and for that I bring forward Baal from Stargate.