I will say that the Etys take getting used to (but I'm glad I finally "got" them). The ER6i's can provide outstanding isolation -- really a major plus if you're listening on a bus, subway, airplane, etc. Good fit can help a lot with isolation and sound -- I like foamies with the Etys, to provide a comfortable, secure fit with a sound that's slightly fuller than it is with the included flanged tips.
They EQ very well, so if you have a player that EQs well, many of the comments about their bass don't really apply -- but most people seem to own iPods, which don't EQ very well. While they still sound good with iPods, the Etys might not be an instant favorite for people who like a LOT of bass ... it took me a while to really appreciate them (after switching to foamies, I liked the Etys a lot).
How much do you want to spend? Can you buy online, or do you need to purchase something in a shop or store?
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Phones (in order of purchase):
Sony MDR71, Sony MDR51, Etymotic ER6, Panasonic RP-HJ50, Shure E3C, Koss PortaPro 2, Creative EP630, Etymotic ER6i, Sennheiser PX-100, Sennheiser HD555, Future Sonics Atrio M5