So I live and work in Manhattan in NYC. I encounter a ton of noise on my daily commute - screeching subways, honking, trucks passing by, etc. As a result, the ability to cancel noise is absolutely critical, partly so I can listen to my podcasts and music, and partly so I can prevent hearing damage by blocking city noise and keeping the volume level on my phone low. I am using apple earbuds and they are functionally useless about 50% of the time due to background noise.
Previously I had these for about a year:
http://www.amazon.com/gp/product/B000XPG2QI/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1
and I liked them. they were great at reducing noise (I rarely went above 3-4 notches of volume on my phone) and had good sound quality, but producing a proper seal was a bit fussy, and they did make a lot of cord noise. One of the cords began to fray as well. That's another thing, my new headphones will ideally be durable, since I will be using them just about every day, for several hours a day.
Currently I am leaning towards earbuds rather than headphones for portability and being less conspicuous, but I unfortunately misplaced my last pair of earbuds so there's that to consider. So mostly I want something hopefully durable, that will produce a superior seal against noise, and have decent sound quality. This is a luxury purchase, but since it's something I use daily and will ideally preserve my hearing I am willing to spend a decent amount of money, balanced by the fact that I'm a clumsy oaf and may lose them again.
Posts
http://www.bose.com/controller?url=/shop_online/headphones/noise_cancelling_headphones/quietcomfort_20/index.jsp
http://www.amazon.com/JVC-HAFX30B-Headphone-Marshmallow-Black/dp/B005FDOG6G
Registered just for the Mass Effect threads | Steam: click ^^^ | Origin: curlyhairedboy
http://www.head-fi.org/a/headphone-buying-guide
If you'd said you wanted cans I'd be all over this like a rash, but you want buds and I don't actually have much experience with noise cancelling earbuds. There is however a thread in Moe's Stupid Technology Tavern where all of us headphone nerds gather and discuss things like this: http://forums.penny-arcade.com/discussion/142270/audiophilia-headphones-amps-daps-and-empty-wallets
If you repost in there you should get some pretty sweet advice.
EDIT: After a few minutes of research, these might be just what you need. The effectiveness of their noise cancelling is apparently a bit more sensitive to fit than some in-ears, so if one of the four supplied sets of tips doesn't fit perfectly, you can always just buy some Shure olive tips (the very best in the business) for a few bucks and throw them on.
EDIT again: These units from AudioTechnica are also highly regarded.