It seems like most people on music forums who want to share their creations do so on Soundcloud or one of the similar audio hosting services.
I'm driven to think: why don't more people just share their music on YouTube? Is Soundcloud's audio quality any better than listening on YouTube at 480p? Is it easier or quicker to upload music to Soundcloud than YouTube?
With YT, at least you can include some kind of visuals with your music, even if it's just a static image of a logo or photo of the band, or your band's info and contact details. And the option to add an all-out video is also there.
YouTube also has a much larger user base, and a higher probability that your audience will have an account with which to add comments.
On the other hand, I quite like Soundcloud's ability to add comments to a specific location in the track (although you can include the time in min:sec format in a YT comment and it will turn it into a link to that location).