Character Rigs that can be used for our monthly Animation Challenges:
PJHogan Character Rig:
HighEnd3D.com's Character rigs:
A bunch of rigs I haven't really had time to go through:
Free props. They are scattered, and a lot of them are .max files, but there are also quite a few .3ds files, and those can be imported into Maya with the .3ds plugin inside bonus tools.
If there are other rigs that I have left out, or if there is more out there that should be linked on this page, please don't hesitate to either add a link, or send me a link that I can post.