Motion library recommendations?

I’m looking for a comprehensive motion library to be used with MotionBuilder (so
characterized FBX files are preferred).

I looked around a bit but none of the sites struck me as great: Dodgy web
pages where I wouldn’t dare to give my credit card details, ridiculous pricing like
15$ for a “sitting on a chair” animation, and so on.

Do you know a good source for canned anims or I’m better off hiring a mocap
studio?

how about this
http://www.mixamo.com/

Some of these are better than others, but the price is right. Most of the motions from the CMU library were converted to be “MoBu” friendly, they are available here: cgspeed - Motion Capture.

Mayur: The customization might come in handy in spite of the price.

WesHowe: That’s the ticket! The CMU lib is awesome, I didn’t know it was
made MoBu friendly.