I picked up a pair of Sennheiser MM50 ip here in the UK for £13 shipped at BargainPile so they can be found cheap and they have been outstanding for sound in the 2 weeks I've used them so far. A brief list of Pros and Cons below:
PROS
They are great at isolating outside noise; Very little bleed through.
Very good sound reproduction from lows to mids to highs - all sounded nice and crisp.
Very good Bass response - may even be a little bass heavy but it can of course be balanced out nicely using the EQ.
Very clean sound even at higher volumes with no distortion even in heavy music.
In-Line mic and "clicker" for basic iPhone/ipod Touch controls like track forward, track back , play, pause.
CONS
It may sound weird but, the small and medium earfittings are too similiar in size and the large is significantly larger so it might be hard to find the right size for your ears.
The in-line clicker button has to be pressed pretty hard, making double and triple clicking more difficult than it should be.
The in-line microphone is not very good and picks up alot of background noise (ironically).
The headset has a short left ear cord and a long right ear cord so it is a little akward to wear in front like a normal set of earbuds (if thats how you wear yours).
Buyer beware in case any of the CONS would affect your decision to purchase or not; Having said that though, I am very happy with this set...