The Sennheiser CX 300-II Precision headphones make a great cheap alternative that work great for most genres of music.
I got these from Play.com for only £15 as a cheap alternative to the Apple headphones and they have surpassed all my expectations.
The CX 300s come in an Eco friendly recycled cardboard box with minimal packaging. The headphones themselves are nicely designed with interchangeable earbuds to make sure you get the perfect fit and a good length cable. They are the sort of headphones that fit into your ear canal so it does take some fiddling to get them to say in.
As for sound quality the CX 300s pack quite a lot of bass for a £15 pair of headphones, surprisingly heavy bass with a crisp and clear sound is produced with all genres of music making them far better than the free Apple headphones.
The only problem I had with these headphones is that the jack is quite cheap and it wore away, coming loose from the rubber coating, this might be an isolated issue but it would have been nice to see a bit more thought going into durability.
Overall these are a great pair of headphones for the price and I would recommend them to anyone looking for a quick cheap set.