On my search for a PC gamepad I found this one. Seems good for the price - looks more or less the same as the official Microsoft one.
PC gamepad similar to the Xbox 360 gamepad design
Rubberised finish for non-slip gaming
All standard features, two analogue ministicks, D-pad, Force Vibration
Digital, analogue and turbo functions
USB connector and long 1.8mtr lead
At last, a quality Xbox 360 style gamepad from Speed Link for PC. The analogue ministicks, D-pad and fire buttons are laid out like the original. The shape with the rubberised finish also gives you great grip in all those tense gaming moments, realistic Force Vibration adds to your experience.