Current best sites to find videos:
-nicovideo - search MMD, mikumikudance, R-18, 紳士の社交場.
-video.fc2 - if you're really patient, or have plenty of money, there are good finds here.
-
toukoucity.to - dodge the porn to get an /e/ MMD prize
-Vimeo - Grab them before they're gone
-Sita's site -
trollvids.com - It's young, be gentle.
-soku -
http://soku.youku.com/v?keyword=mmd - Chinito site
List of free apps/addons (google them) that might help you with downloading vids:
NicoFox
Downloadhelper
Freemake Video Downloader
JDownloader 2 beta
IRC /e/roMMD chatroom with famous people in it!
Mostly idling so you might want to leave the tab open and wait for an answer.
#erommd at rizon
MMD /e/ STARTER PACK, get content creating!
https://thepiratebay.se/torrent/11039741 