I've spent hours and hours listening to a zune, a d2, sony 738, and sansa fuze/clip. I mainly used my shure e530, sometimes senn. hd595 and no eq or sound enhancements. These I consider the top contenders for me. I already have an touch 2g which I think sounds awesome, just lacking some definition sometimes. Anyways, here are my thoughts, and know I am obsessive/compulsive for real. I beat a dead horse to death so to speak, if you know what I mean. So here is just one "nut's" list in order of SQ only.
1. Fuze/clip- at first I didn't like the presentation, but it has everything covered and has no major weakness. Great organic sound and great detail- definition and soundstage- smooth yet detailed and very musical.
2. ZUNE- this is one fine sounding dap, everything is present with no major weakness. The fuze/clip just sounds a little fuller (more 3d with my cans) but A+ none the less.
3. Sony S738- very musical and warm but with plenty of detail, but percussion can sound a little off and lacks somewhat in power. Not quite as neutral as 1 and 2 and slightly aggressive- which can be good sometimes- Or not so good, depending on the music. still an amazing dap.
*Tie- Ipod touch 2g- I like the sound very much! great highs, lows, mids and awesome detail and big soundstage. But when music gets complicated some stuff blends together (bad definition) unlike the others.
4. Cowon D2- great separation of instruments and powerful amp, good detail. Things can somewhat sound synthetic with this dap, like percussion and vocals, plus it lacks body and has a small soundstage. The bass is also not as good as the others IMHO.
Please keep in mind these are all great daps and I am splitting hairs here and it is very subjective/personal of course. Plus when you throw different cans into the mix, all my observations could go out the window and my order could change. Also these where all HO , no amp involved. And if I used eq, the order would definitely change.
So yes. fuze/clip is my favorite