very easy answer... If you have the Sandisk M series and bought it between 10/3/2005 and 2/28/2006 you will want to use Rhapsody - here is why:
Sign up for a 6 month commitment for $90 ($15/month) and since you bought a sandisk you will get an $80.00 rebate. SOOOOO... $10.00 TOTAL ($90-$80) for 6 months of to go service!!!!!!! TOTAL - Not $10 PER MONTH - TOTAL!!!
I have only used Rhapsody, so I am not qualified to compare them to Napster etc. BUT I can say to date I have found Rhapsody to be easy to use, have plenty of selection etc.
Note - be careful in what service you sign up for. Usually there is a base subscription service on these sites for like $10/month. That allows unlimited streaming to your PC. BUT if you want to transfer to a player, you need a "To Go" service, which is usually more like $15/month
But again, if you have the Sandisk Sansa and do not do this $80 rebate you are crazy.
Which is the best music subscription service looks like yahoo is 10 bucks a month (to use for a mp3 player). I looked at rhapsody and couldnt find a price on their service. I new to this i just got the Sandisk player. So which one is the best price and value?