VLC is the best media playback program IMHO. Free, fast, light-weight, works with pretty much all media file formats, can sometimes even fix damaged media files, and so much more. Some other players can come close, but from what I've tried out myself, they won't beat VLC. On the few Macs that I've used, Quicktime was okay most of the time, but I still preferred VLC. I've only tried two or three others on Macs because I generally don't use Macs nearly as much as I use Windows or even Linux computers.