SoundCloud - Enjoy music & follow favourite artists
Soundbar - A lightweight SoundCloud player for Mac
yungcloud - "the world's leading underground music streaming service."
BeardedSpice - BeardedSpice is a menubar application for Mac OSX that allows you to control web based media...
Artrezor.com - New beta social network for sound lovers, including waveform player and uploads. And it's free.
Cumulus - A SoundCloud player that lives in your menubar.