In Xiaolin Showdown fic Demon Of Wind, while Rai did choose to become Wuya's apprentice and is not without flaws, it's made pretty clear in the story that he never had any personal grudge against Dashi or his students and infact by the time he was finally turned to stone he was only staying with the Heylin side because he had to.
In Fate Zero Sense, Kirei and Wade manage to be this andCard Carrying Villains at the same time. While they are both unrepentantly evil, they also work for the author and follow his orders and when not being evil or breaking the Fourth Wall they live rather normal lives.
Yu Gi Oh The Thousand Year Door has Lord Crump, most of the time. He is a suck-up to the Queen, but the only time he ever seems truly malicious towards anyone is when under the influence of the potion of bravery.
The Pony POV Series has Rancor, Discord's little sister, in the Dark World Arc. She only becomes one of his Co-Dragons because Their Parents ordered her to do so and when its not her turn to fight the heroes is a Friendly Enemy, complimenting them and even helping undo some of the Valeyard's damage by giving Apple Pie the ending of the comic (revealing it had a Bittersweet Ending instead of a Downer Ending) he used as part of his efforts to Break the Cutie. As far as she's concerned, its Nothing Personal. In fact, when she finishes her mission (stealing Destruction's power back from Discord, mortally wounding him in the process), she opens a portal, tells the heroes goodbye, and leaves to do her real job as an Anthropomorphic Personification.
Chef Hatchet in The Legend of Total Drama Island does his job (which frequently involves making the contestants' lives more difficult) in a conscientious and workmanlike fashion, but he'll also help the contestants out from time to time if it doesn’t conflict with his duties. He agrees to conduct the funeral service when Chris can't be bothered, and his attitude toward Sadie after her ordeal during the camping challenge could even be seen as kindly.
The Acolytes of Pein, from Naruto fanfic A Growing Affection, don't particularly like what they are doing, or what it does to Nagato, but they are unflinchingly loyal to him.