Did a search and nobody has mentioned these...
I needed a pair of cheap knockaround earbuds for iPod, MacBook, airplane listening. Anything but the crappy stock white iPod ones. So I got the Sony MDR-EX36V.
They're $30 at Best Buy and you can get them online cheaper. The bass is surprisingly good, the frequency response (6-23k) is better than other brands at this price level (Skull Candy, etc.), and they are amazingly comfortable. I can barely tell they're in my ears.
They don't advertise noise canceling, but they still block a lot of ambient noise. Highly recommended. Best purchase I've made in a while.