I've been eyeing up the Gamester Phoenix Revolution for a while now. I'm normally skeptical about 3rd party products so i was weary to drop $24 on it but christmas cash made it worth trying out and all i have to say is WOW.
What makes this controller special is its modular units (d-pad, both analog sticks, and the regular buttons). they are interchangable so you can make the controller the way you want to use it and you can change it around when ever you want. Also the analog sticks have adjustable stiffness and an invert switch for FPS games.
The controller has a great weight to it, a nice cord length, and is surprisingly comfortable for being slightly larger than a regular ps2 controller.
heres the uk site with pictures
http://www.radicauk.com/product/74160.htm