Shure E5c

The only in ear phone on the market today that is better than the shure e5cs is the ultimate ears ue-10 pro, however these require a trip to the audologist for a custom mold, and they cost 1,000, so they are absurd unless you are really a professional musician. That said, the shure e5cs deliver studio quality sound without being excessively expensive (you can get them online for 350 or so).
Bose headphones are a joke compared to the shure e5cs. But then again, that should come as no surprise, because Bose is to audio equipment what apple is to computers - a maker of vastly overpriced, low quality products that are marketed to morons who don't know any better. Like I said to my friend, if you want a nice 100 dollar pair of headphones, buy the Bose QC2s, except that you will get charged 300 dollars for them.
As for the ETYs, they are decent, and nothing more. The CNET editor who reviewed the ER-4 clearly doesn't know much about high end audio equipment. Sure, if you've never listened to audiophile level headphones before, and put on ETYs, you will think wow, aren't these great! Fact is, their bass is decent at best, although their fidelity is above average. In every way, the shure e5cs outperform the ety er4s. But then again, thats what you should expect, since you have to pay about 60% more for a pair of the Shure e5cs. I mean, you would expect a ferrari to be better than a lexus, right? You get what you pay for. So, if one is willing to enter this segment of the headphone market, I would suggest saving your money for a pair of e5cs rather than doing it on the cheap and getting ety er4s.
Lastly, the shures are actually worth the cost, you will smile as you discover a whole new world of music.

I own the E4c's and just purchased the SE530's (same as the E5c). Wow! The bass rocks! I bought the E4c's on ebay for $180 and the SE530's for $312. Is it worth the difference. If you like bass, then yes. Not that the bass on the E4c's is bad, just not what the 5 series offers. Both have wonderful mid tones and brilliant sound balance. The sound reproduction make these truly a pleasure listening to these. I also like the oval shaped case that the 5's come in (versus the round case of the E4c's) but its obviously not a big deal. Both cases are nice. The big difference is the bass. MUCHO bass!!!