I really like Tabletop Audio. It's a great tool for anyone who's running a Tabletop RPG, or for writers who're looking for atmospheric background music. There's lots of different genres represented (much more than typical fantasy stuff). I've been using the site for a while, but I just discovered the new SoundPad feature.
SoundPad was designed for those of you who wanted more control over your sonic environments. Instead of fire-and-forget 10 minute ambiences, each SoundPad is made up of a few dozen sounds, divided into categories.
I've spent a bit of time today playing with SoundPad, and it's really cool. Instead of hunting for just the right atmospheric music, or just defaulting to the Skyrim soundtrack, I can tweak and tune the music, and sound-effects in the game. One of the coolest features of SoundPads, and playlists, is the ability to send live links to the music/sounds you're mixing.