I have a set of Bose headphones from the outlet store here in Connecticut... they were $129 and the sound is unbelievable, I rarely use them anymore since I got my gaming headset (I bought them originally to play rock band) but they really are great and a nice alternative to the Dr Dre ones that are like $300 bucks
Bose is where it's at for me. Reasonably priced and excellent sound. Here are the ones I travel with: http://www.bose.com/controller?url=/shop_online/headphones/audio_headphones/in_ear_headphones/index.jsp Super comfortable and stay in your ear with multiple tip sizes that come with it to fit your ear best. They don't take up any room to speak of, so really easy to travel with. Also has an excellent mic if you're using them with your phone. These blow the iphone ear buds away by a long shot. If over the ear is what you're looking for, my dad uses the bose quiet comfort and they are sweet. They're like 300 bucks, but bose has stuff from around $50 on up from there.
These things have incredible sound, fold up and have a lifetime no-questions-asked warranty, also bullet proof. The only drawback is that you look like a reject from the 80's, which is what we are I have a pair from ebay, they are all I use. Since they are not in-ear there is sound leakage but I find in-ear ones uncomfortable and they fall out all the time.
If you want incredible sound and closed-ear listening, check out the Sony MDR series. I bought a pair of them 11 years ago for use on-air. After all that time, they still sound great and are in great shape, even after getting beat up daily.