Sennheiser MX 270 In-Ear Stereo Headphone with Dynamic Sound
Price: $15.99
http://www.amazon.com/gp/product/B00...ls_o00_s00_i00
Amazing sound for such a cheap price. I make sure I have an extra stashed away just in case I break / lose my current pair.
Bonus tip: There is a small bump on the left earbud. You can use it to determine which one goes in which ear by touch alone!