I've recently started using a download service in addition to eMusic - payplay.fm. You can read a review from PC Magazine.
eMusic is still my primary download service. It has a much larger selection than payplay and better pricing (my eMusic plan breaks down to .25/track while payplay is .88/track). With eMusic you pay a subscription fee for X downloads/month. Payplay is pay as you download. The flexability is nice even if pricier than a subscription.
Even though eMusic has a larger selection payplay is sometimes more comprehensive. For example the material that got me to try payplay in the first place - Red Molly and related artists. I had picked up Red Molly's Love and Other Tragedies on eMusic. It was good enough to make me want to try the various members solo projects. eMusic did have Laurie Macallisters These Old Clothes and Abbie Gardners self-titled EP. Payplay has quite a bit more - Macallisters The Things I Choose to Do, Gardners Honey on my Grave, and Carolann Solebellos Just Across the Water as well as Red Mollys self-titled EP and first album Never Been To Vegas.
Two other albums I consider 'scores', though. Buckner and Garcias Pac Man Fever album (I bought this on vinyl in '82!) and Barnes and Barnes' Voobaha. I'd been casually looking for that last one for 28!!!! years.
Very casually, obviously.