super.fi 5 pro.
I have them, and after about 150 hours or so, they become so much more then many out there. As far as IEM's go, i own Ety 6I's, above mentioned UE super.fi pro's, Shure e5c's, and the new apple buds.
As far as sound quality, i would suggest the super.fi. just because they've got a full and detailed sound which i find hard to describe more thoroughly.
the only issue i have with these, is fit. they're large and therefore make maintaining a seal an issue. my solution was to swap monitors- where i wear the left monitor in my right ear and vice versa. Only now, a year and a half later, have i gotten fed up enough to order some foam tips designed for it from complyfoam.com. That should solve the problem, as my equally bulky shures are super-compfy just because of the olive foamies.
The ety's are close contenders as far as SQ, but in general, are a real pain to use.
The Shures are more detailed, and i believed aimed for studio use. Naturally, they play music as accurately as i've ever heard, representing the highs, mids, and lows, in my mind, as they should be. however, i'm a teenager, and therefore a bass head (I apologize to those non bass-head teenagers out there. i have yet to meet one of you) find them particularly bright.
Also worth considering (don't jump at me!) the new apple in-ears. They are surprisingly cheap and good duel-armature headphones. at $80, the value is outstanding! after several hours burn-in, they are staggeringly good for the price range. one of the most underrated headphones i've tried.
so to sum it up, i suggest in this order:
UE Super.fi 5 pro (pro because of the replaceable cables, which are useful)
apple buds
etys 6i
EDIT: i just succeeded in putting a pair of shure olive foamies on my etys. whoa. improvement (also, it's amped, but improvement unamped too!)