Rainy Mood.com is a simple site with no other purpose than to emulate the natural sound of rain, thunder, birds and wind within a 30 minute loop. Alot of people like myself enjoy listening to rain or even the sight of it as it's a well known fact that is has been found to be relaxing even as babies.
If im feeling slightly down or just in a relaxing mood and I have no-one else distracting me then I would tend to simply listen to this awesome loop and chill, possibly listening to some other music with it as alot of things tend to mix VERY well.
So I suggest you check the site out if you haven't already. If you find something similar, or even find a good relaxing song to mix with the loop, post in the comments!