Speaking as someone who rarely signs up to ANYTHING on the internet, I have to say that eMusic is the BEST $10 a month that a music lover could ever spend!!
GOOD POINTS:
Huge variety of genres/artists. High quality VBR mp3 files that can be copied/used as you wish (eMusic trusts you not to act like a criminal). Handy previews for each track, with ability to download individual tracks or whole albums or "stashing" a bookmark for that album to download later. Flexible searching by artists/labels etc - discover wonderful labels you never even heard of! Helpful message board community who can point you in the right direction for inspiration/troubleshooting etc.
BAD POINTS:
None really, but..
You have to use eMusic's download manager which queues tracks up to 45 at a time. Also, you don't quite get the "unlimited" downloads implied in the advertising. When you reach about 2000 tracks per month, and automated message is sent to you advising you to "cool down a little". You may get cancelled if you keep high D/L high amounts.... I accept this as a necessary safeguard to the service, to prevent the whole system grinding to a halt. 2000 tracks for $10 is still a bargain (how much does 2000 tracks cost on Apple's service?)
You will soon find that you HAVE to buy a new hard drive to fit all that great new music you've got ;)
FlaGranny, you may like some of
This or
This