Which headphones should be purchased?

Suggest you check out the forums at headwize.com and headfi.org. Use their search engine and you should find some useful info. I would avoid the Bose headphones. For traveling I use cheapo noise cancelling headphones which stink sonically. In the fall and winter, I usually use Grado RS-2 headphones, which I personally prefer over the Sennheisers. The Sennheisers are good, but too difficult to drive compared to the Grados and Ultrasones. In the summer, when the a/c is on and I want some isolation I use the Ultrasone HFI600. This particular Ultrasone is a sealed back headphone and is the only sealed phone I have found that rivals an open back phone in spaciousness and soundstaging. I have tried various sealed headphones such as Sennheiser, Sony, Koss and Denon but have found nothing that rivals the Ultrasones, which are not widely distributed or well known. They are mostly sold in the US thru pro audio dealers or are available at meier-audio.com. Tonally, they are to headphones what the Spendors are to loudspeakers. Yes, they are even a little smoother sounding than the Grados. You may not like the way they look either. However, for plugging directly into a portable and for a sealed back phone, I have found nothing better. I think Ultrasone may have changed the design of the HFI600 since I got mine and the current model looks better and folds up, but may not be as comfortable. Good luck and enjoy.

Has anyone heard the Bose headphones and compared them to the Sennheisers or other audiophile Headphones?

I own several high-quality headphones, including a Sennheiser HD-600. A friend of mine let me hear his Bose noise-canceling phones. It was not a good test for sonic quality. We were using his music, his personal stereo and the test was quite brief, so based on that test I can say that I was not wowed by the fidelity or sonic quality, but the noise-canceling ability of the phones is quite remarkable. If I were making a choice for the application where you wish to use them, I would carefully audition the Etymotic's vs. the Bose. Ultimately, I think that the sonic quality of the Etymotic's will override the Bose which, at least in my poorly set-up listening test, did not come close to a high quality headphone.

I use the Etymotic 4P (higher output with slightly rolled off highs re 4S) for exactly the purpuse you describe. They're great and easy to pack!

I fly several times per year to London on American Airlines. They provide the Bose headphones in business class. I had considered buying a pair of my own for when I travel on my own dime, but I did as Joe-b suggested and checked out Head-Fi and Head-Wize. I ended up buying a portable Headroom amplifier and the Etymotic ER-4P's from Headroom {url=http://www.headphone.com/layout.php}Headroom{/url} several months ago.

I have compared the Bose directly with the Etymotics and the audio performance is significantly better with the Etymotics (an understatement!). They also do a good job of isolating outside noise. The Bose cans do a reasonable job of isolation, particularly the engine noise of a 777.

The Etymotics have received many favorable reviews and are frequently mentioned as headphones to consider for quality audio as well as significant isolation from external sounds. Some folks find the design of the Etymotics a bit problematic, they are "canal phones" and need to be placed into your ear canal. They have several styles of tips (one is rubber, the other is foam), you may find one type more suitable than the other. They took me a little while to get comfortable with them, but it was well worth it.

Hope this helps,
Bob