Your parent mentioned the MK5s. Etymotic prides themselves in pretty flat response overall, with some slight variation in different lines. I've had a couple of different versions of the ER-4 (ER-4PT, ER-4XR) and have been happy with them. I think the primary thing is whether you're comfortable with the form factor, and for that you can just pick up a pair of the ear plugs for less than $20. If you're happy with how they fit, the particular model of headphones you pick depends more on how much you're willing to pay.