>>2078548I've personally tested all of these and can confirm they work.
>>2074777There are probably a ton more that basically function the same way.
>>2079085An anon made an archive of quite a few of them here:
>>2075148If you want to download videos yourself though:
For a browser extension, I use Video DownloadHelper. It's available on both Firefox and Chrome, and can grab videos from pretty much any video streaming site, though the Chrome version can't download Youtube videos because Google won't allow anything in their webstore that affects Google websites in ways that Google doesn't approve of.
For a dedicated downloader program, I use JDownloader, which comes with plugins for thousands of websites including nicovideo. You'll need a nicovideo account for it to download from there though. It's also useful for downloading entire image galleries and stuff.
