BKGaming: Pretty much all music is DRM free nowadays, and yea that includes itunes. I buy my music from Amazon because I use them a lot and I prefer the MP3 format, music is DRM free there too.
adaliabooks: ^This
As far as I'm aware most of the major stores are DRM free these days. Amazon and Google Play (Not 100% sure they are DRM free as I've never purchased from them, but I believe they are) are both big and should have pretty much any major artists, and I can vouch for Amazon's DRM freeness as I've purchased from there in the past. iTunes is also DRM free but can be a bit more hassle actually making use of your music if you don't use iTunes and Apple products (as far as I'm aware the only option to get music from iTunes is still in Apple's own format, so you'd have to convert it)
Amazon's also great as if you buy a CD they automatically give you the digital versions straight away (in the UK anyway, not sure if it's a worldwide program), and they keep a back up for you, in case anything ever happens to your CD.
I love Amazon - they have a huge selection and their "AutoRip"-Feature is supercool.
I remember the day, when I logged into Amazon, and out of a sudden a whole bunch of MP3s were downloadable for free, only because I had bought the CDs some time ago.