How to animate a 2d character

Is there a built in feature for animating a 2d character in Unity? I have seen this approach using AnimatedTextureUV but is this really the best way of doing it? I am looking for the best way to animate a 2d character using a spritesheet OR multiple images.

Yes, using a spritesheet and animating the UV offset is the best way of doing it.

There are multiple tools to ease the process. Besides the script you linked to yourself, there is also SpriteManager on the UnityCommunity wiki, or you can buy SpriteManager 2 on the Asset Store.