One of the most popular sets of cheap earphones is Panasonic's ErgoFit RP-HJE120, which you can find online for around $7. It offers impressively decent sound for the money and a comfortable fit, which is why I gave it four stars.
But the RP-HJE120s aren't the only sub-$8 earphones that sound surprisingly good for the money. At this price point you'll also find iLuv's City Lights earphones, as well as the JVC Gumy Plus (HAFX5) reviewed here -- and a few other models I haven't reviewed yet.
The Gumy Plus doesn't offer quite as accurate sound as the Panasonic ErgoFit RP-HJE120, but it, too, is a well-balanced set of earphones, it fits comfortably, and its cord doesn't tangle as easily as the Panasonic's.
Design and features The Gumy Plus comes in a variety of colors. There's nothing fancy about its all-plastic construction, but it's an attractive enough looking earphone and lightweight.
Like the ErgoFit RP-HJE120s, these are sort of hybrid earphones, part hard earbud like your basic Apple earbud and part soft bud. They come with three different-size pairs of silicone eartips. At this price, you're more apt to see hard-bud earphones, but being able to jam the soft tips into your ears helps with sound isolation and maximizes the bass output. I was able to get a tight seal with the largest of the eartips, and I as I said in the intro, I thought the earphones were comfortable and they stayed in my ears well.
As you might expect for a $7 pair of headphones, you don't get anything in the way of extras: no inline remote/microphone for making cell phone calls nor any sort of carrying case.
While the Panasonic HJE120s have an L-shaped plug, the JVCs have a compact straight plug that will be easier to fit into more smartphone cases but may not be as sturdy as an L-shaped plug.