I have to say that I've fine-tuned an excellent mix through Pandora... lots of Harold Budd, Brian Eno, Windy and Carl, STOL and then sometimes there are these oddball artists thrown in that have like an ambient-space one-off which is cool... Pandora offers the ability for me to share this, so if anybody would like to hear what I'm hearing let me know, and I'll add you to the mix, I think it requires an email address or something or you can look up my username: mattborghi, I believe...
There have been a variety of sites over the years that have tried to do something like Pandora, but so far Pandora is the best, and it really works excellently!