At first, the ideal site for streaming Mega Man music was Atomic Fire (then the Mega Man Network). But then they messed with the organization, and you have to download it all if you want to listen to something. So does anyone know any other good site for Mega Man music?
Megaman Network is the best you're going to get, honestly. I've never seen anybody else with such a complete list. Downloading bulk isn't very fun, but I imagine that it's better on their server since hosting so many mp3s would invite endless downloads, repeat downloads and hotlinking. I'd suggest doing what I do: burn what you pull from the site to a data disc and all your problems are solved! Just refer to your "archive" to pull whatever you need whenever you need it and not put a strain on your hard drive! =D