Adobe Flash, 3DS Max, Zbrush, Anime Studio, Photoshop, Toonboom, are good for creating animations from 2D Games, Anime Shows, Movies, 3D Games and more. As for the "best" there is none. I use Adobe Flash, Photoshop, Zbrush, 3DS Max and plan to buy Toonboom Animate Pro 2 for other projects. As for creating your own "animations" that is entirely a different story all together.
These all are good ones. But how about the online like animoto?