[l1lJ]

Hi, I was wondering what headphones have the best noise isolation / cancelation or ambient noise attenuation? Thank you very much.

 

[Ashade]

If noise cancelling is your highest priority: Bose QC15.
 
If you want something else you might want to check Jaycar Pro Monitor. Good isolation, awesome price, neutral sound... 
 
What are your preferences?

 

[l1lJ]

Thanks. I'm not sure what you mean by preferences sorry, but ambient noise attenuation is the highest priority.

 

[Steely Dan]

As far as on ear headphones with only passive attenuation, I'd go with DT1350s.  EMIs are probably the way to go if this is your number one priority though.

 

[TheJazzyH]

Anything else you're looking for in a pair of headphones? Budget? Music/sound preferences? What kind of noisy places would you take these headphones to? How important is comfort or durability to you?
 
In-ear headphones can have better passive noise isolation than the best noise-canceling headphones (like the QC15), since they basically double as earplugs in function. Be careful, though, as some of them do it so well that you wouldn't be able to hear a car before it runs you over, among other possible hazards.

 

[Armaegis]

For absolute isolation, a well sealing pair of iems is the way to go. The original Etymotic ER-4p and 4s used to be one of the best, though there are many options these days. If you need even more, some ear protection muffs on top of the iems will chop out noise even more. You can even get active noise cancelling muffs.
 
For noise cancelling headphones, bang for the buck the Audio Technica ANC7b is my top pick.
 
For passive cancellation: Sennheiser HD280/380, HD25-1, Beyerdynamic DT770