if you wanna pay some money you can try mixamo, ready to use, good previews, I got some free samples and they work (fine for Unity
).
if you can convert and correct mocap files in mainly .bvh .fbx .dae formats, you can try these free collections (>1000 files):
http://www.thetrailerspark.com/index.php...ect&id=1004 (I just downloaded some and will test them when I have free time)