What are the best earphones to use in the $100-$150 range? I've done my research but I came out more confused. The iLounge iPod Guidebook recommends the Etymotic ER-6i. But the people here talk about the Shure and Sennheisers a lot. Then there's the Shure E2c, E3c, all the way up to the E500... I don't know what the difference between all these models. And while where at it, what's the difference between the E and the SE models?