An American Tail: Fievel Goes West: Cat R. Waul is a cultured, well mannered "gentlecat" who lures New York mice out west in order to turn them all into "mouseburgers", because simply chasing and eating them is an "unnecessary expenditure of calories".
Gru is gradually softened into this over the course of the story.
El Macho from the sequel counts too. It's pretty clear he's incredibly nice, even after he's revealed himself to be Not Quite Dead.
Frozen: Both Hans and Duke Weselton are this. Both will kill to have their way (for Hans to get Arendelle's throne and for Weselton, to secure trade advantages) but show care and concern for their soldiers as well as the people of Arendelle.
Kaa, despite wanting to eat the hero, comes off as very polite and soft-spoken.
Lilo & Stitch: Jumba Jookiba may constantly boast over his status as an evil genius, and he may have created over 600 super-destructive aliens, but he's a pretty decent and sociable guy overall. He even gets a Heel-Face Turn near the end of the movie.
The Little Mermaid: Ursula is pretty hilarious, and when King Triton confronts her about Ariel's Faustian contract she greets him with a, "how are you?"
Monsters, Inc.: Waternoose is legitimately avuncular with Sully, and is sincerely regretful when his plans require trapping him in the human world. He even tells off his Mook for not being half the monster Sully is.
The Princess and the Frog: Dr. Facilier, the witch doctor. In the words of Prince Naveen, he is "very charismatic". Even when he's manipulating the prince's butler and summoning help from his Friends on the Other Side, he's always polite and cordial. Except when you put his voodoo amuletin danger.
The Sword in the Stone: Madam Mim is cheerful, amiable, and actually pretty friendly when Arthur blunders into her house, and while he can tell she's unpleasant, he doesn't even realize she's dangerous until she tells him she has to kill him which she says with about as much fanfare as someone saying it's suddenly started raining. Thought she's more a mix of this and Faux Affably Evil, sometimes her true nature slips out to show just how crazy she really is before she pulls herself together.