I like Magnatune. They are an independent record label, releasing music across a broad specturm of styles. You can find their website here. I got one of their emails this morning alerting me to a new web-based music player that plays their catalogue. It's excellent, a good piece of programming. This link takes you to a Jazz/Tango album that I partularly like.
I have always found the quality of their recordings and musicianship to be exceptional. And if you take out a subscription, the ads disappear, you can stream the music at will from their website, and/or download "all you can eat" in the highest quality formats available. The player below is a bit ordinary in style but it will show you what I mean.