Well, Amazon MP3 is a big winner as far as I'm concerned. I just downloaded Feist's "1234" for 89 cents, DRM-free. It's only available with DRM in the iTunes store (and for ten cents more), and as a reviewer pointed out, oh the irony--this is the music from the new iPod nano ads. Ha!
I also bought the long version of "Call Me" by Blondie, which isn't even available as a single download on iTunes. That made me HAPPY! (Yes, I admit I feel guilty too, Blondie being the very definition of a guilty pleasure.)
The Amazon mp3s are encoded at 256k (variable bit rate), which still doesn't sound as good as a 256k AAC file, in my opinion. But frankly, the price differential (99 cents for Amazon, versus $1.29 for iTunes Plus) makes the difference. And of course, if it's a choice between DRM and non-DRM, it's a no-brainer.
(I'll still buy full iTunes Plus albums, rather than the Amazon version, though, as the price tends to be the same in that case.)
Long ago I decided that what's good for Apple is good for me. So I'm hoping that NBC/Universal and Apple will work out their differences, and the songs on Amazon will also be available on iTunes Plus. And here's looking forward to the day when all digital music is DRM-free. It's comin'. It's comin'.