AnimProps is a website where 2D and 3D artists can create an account for free to share, sell or purchase artwork. A big resource for animation rigs.
Built By Colossus Rigs
Built By Colossus Rigs are free and paid Maya rigs available for download. Founded and run by Roman Jeffery.
Animation Paper – Pre Release
The Animation Paper – Pre Release is now available. Currently in Alpha but check it out, download it and give feedback
Fantasy Crocodile Rig (FREE)
Fantasy Crocodile Rig is a free Maya rig that has a super appealing design.
Akeytsu
Akeytsu is a piece of 3D animation software and is a lighter, faster and cheaper alternative to Maya. It also has a free educational version.
Rocket Girl Rig (FREE)
Rocket Girl Rig is a free Maya rig from the VMComix animation blog.
Jasmine Rig (FREE)
Jasmine Rig is a free rig for Maya that has a load of great features!
Morgan Loomis Tools
Morgan Loomis has a bunch of great animation tools and scripts for Maya on his website free to download. You can download the full animation shelf or get them individually!
Animation Paper (FREE)
Animation Paper is a popular free software for hand-drawn animation created by Niels Krogh Mortensen