I used to go with alpha waves overlaid on my favourite music (using free software I'd downloaded), and there was a blog called "binaural banjo" I used to like, but after a while I just got irritated with the ever-present tones. Then I read about it further and learned that although it's true one's brainwaves get "entrained" to match the beats, there is no evidence that it actually *does* anything (either positive or negative).
What IS essentially proven to work, however, is plain old mindfulness meditation, which can be performed in myriad ways: With or without guidance (free recordings are available all over the net, including as smartphone apps), in silence, or with relaxing music or background sounds (like thunderstorms, ocean waves, bells, or even the sound of a train clacking along on the tracks). =)
I don't use any I just use my vaporizer now