Choosing the "best" JavaScript library for animation depends on various factors such as project requirements, personal preferences, familiarity with the library, etc. However, some popular JavaScript animation libraries include GreenSock (GSAP), Anime.js, D3.js, Velocity.js, and jQuery.
GSAP is often regarded as one of the most powerful and versatile animation libraries with a vast range of features and great performance. Anime.js is known for its lightweight size and simplicity, making it a great choice for small projects. D3.js is primarily used for data visualization and offers robust support for creating interactive charts and graphs. Velocity.js and jQuery are widely used libraries that offer a variety of animation features and have been around for many years. Ultimately, the choice of the library depends on the specific needs of the project and the developer's expertise with the library.