To serve as a noise blocking white noise machine (that is the main use of the site) but only with natural sounds, this one is my favourite (try with the Animate feature) : http://mynoise.net/NoiseMachines/windSeaRainNoiseGenerator.p...

In general, all the latest ones have my preference, as I am perfecting my skills, day by day. I am quite happy with the last one added two weeks ago: http://mynoise.net/NoiseMachines/circularBreathSoundscapeGen...

Check this one if you like sung voices: http://mynoise.net/NoiseMachines/himalayanVoicesSongGenerato...