In the previous post I dumped a bunch of movies from my own collection on you. Here are some others from the web, which (selfishly) is biased towards my own movies, just because I had the links. Check out the channels though, of these dedicated YouTube users who’ve compiled really great stuff.
https://www.youtube.com/watch?v=QVf0NslLHo8
https://www.youtube.com/watch?v=ws2V-Sv8-GQ
https://www.youtube.com/watch?v=Z8CRDDt1RJw
https://www.youtube.com/watch?v=v39UtTfOHAU
https://www.youtube.com/watch?v=_FlGiqPdbx8
https://www.youtube.com/watch?v=odZDIU8sPLw
https://www.youtube.com/watch?v=KHDRDmujTug
https://www.youtube.com/user/djxatlanta/videos
(wonderful, now discontinued, cannel)
http://www.skyandtelescope.com/astronomy-news/galaxy-merger-movies/