Anyone have advice on what noise cancelling ear buds to buy, specifically for airplanes and being a passenger in a car?

Don't really have a budget. Under $100 seems ok.

 

Etymotic Research, Inc. - High-fidelity Earphones, Headsets and Hearing Instrumentation

 

On the cheapo end, I use these: Plug In-Ear Headphones | Earbuds & In-ear Headphones | Koss

While not active noise cancelling, they work in the same fashion that the foam earplugs do and really are very effective at isolating sound. You compress the foam and insert the earbud. The foam then expands to fill your ear canal.

I recommend against the model that has the inline volume/mute switch as I found it to be a failure point.

 

Im very fond of the Klipsh S4i's and S4ii's. I have both and they are great. They don't have active noise cancelling but when you have them in you can't hear much of your surroundings without audio input. Once you turn on the tunes even quietly I can't hear anything in my surroundings.

 

I use the Klipsch X7i's. I travel for a living and they do a great job of sealing in your ear canal and blocking out all outside noise. They also sound better than any other in ear headphone I've ever tried.