I also have the Klipsch S4s and I do not regret the purchase. Fit can be iffy, though. I have also heard good things about the Sennheisers, but I have no experience with them. I used to have the Maximo IM-590s, but while the sound was good, the construction was too cheap and they only lasted a year.
I have heard that any Skullcandy products are over priced for the quality, but again, I have no experience.
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