I've used a pair of Sony Fontopia earbuds for my iPod for many years. In-ear earbuds are very much a matter of taste, but I really like them for the passive sound isolation they provide, and for the full sound with rich bass. However, my old Sony phones parted company with the mini-jack plug, so I was looking around for a replacement. I probably would have just settled for another pair of the Sony earbuds, but I had some money for my birthday and felt like treating myself. I'd listened to the Shure E2c phones at the MacExpo, and was very impressed by the clarity and warmth of the sound. Yes, they are a lot more expensive than the Sonys, but they sound a great deal better too, so I feel like I've got good value for money.
I've been using them for a while now, and I'm really pleased with them. As with any in-ear phones, the fit is very important. Shure provides three different types of sleeve: foam, soft rubber and firm rubber, and each is provided in three sizes. It's well worth spending some time experimenting with the different sleeves to find which suits you, because the sleeve needs to be slightly compressed in your ear canal to provide rich bass and proper sound isolation. It took me a while, but I ended up using the soft flex sleeves which are quite similar to the ones provided with the Sony earbuds.
The other slightly odd thing about the Shure phones is that you wear them with the cable going over the top of your ear and tucking behind it, rather than with the cable dangling down, which is more usual. A plastic sleeve on the cable can be slid up to hold the cable taut against the back of your neck or under the chin. A word of warning - don't wear the cable under your chin, because you'll look like an idiot. Inserting and adjusting them takes a little practice, but once you've got them secured, they are very comfortable. The isolation is really excellent, and even on a noisy train I can have the volume quite low and still feel enveloped by music.
They do have another quirk, however. The body of the earbud containing the driver is slightly pointed, and I do sometimes feel like an exponentially less glamorous and beautiful version of Lt. Uhura. I have to fight the urge to press my finger to the earbud and say, "Captain, we're being hailed by the Romulans!"