Source Filmmaker is a free movie-making tool built and used by Valve to make movies inside the Source game engine. It is a full package and can be used to make cinematics using Valve models and environments.
Source Filmmaker (FREE)
Kinovea (FREE)
Kinovea is video player that allows you to slow down, study, draw and comment. Primarily made for sports enthusiasts but useful for animators too.
Animation Paper (FREE)
Animation Paper is a popular free software for hand-drawn animation created by Niels Krogh Mortensen
Daz 3D (FREE)
Daz 3D – A 3D morphing, posing, animation and rendering suite, normally retailing at $249 but is now free to download
Pencil 2D (FREE)
Pencil 2D – An animation software for vector and bitmap graphics. It is free, multi-platform and open source
Synfig Studio (FREE)
Synfig Studio – A free open-source 2D animation software
After Effects
After Effects is an adobe product and is a very popular motion graphics and visual effects programs. Useful for editing and adding post-effects to animations.
ToonBoom
Toon Boom Animation is the leading supplier of animation software and storyboard software for animation studios and media publishers.
Adobe Animate
Adobe Animate allows you to design interactive animations with cutting-edge drawing tools and publish them to multiple platforms.
Animator's Resource Kit 