I've been after a gamepad for a while and could never get around to it. When I was this on Mighty Ape, I though it was worth a try.
Easy to use USB, setup up took less than too minutes.
The buttons are responsive and the analogs work fine. It has an interesting feature that lets you swap the D-Pad and analog; basicly switching between an XBox 360 style control and a PS2 style control.
Now my favorite feature is the gamepad profile application that comes with the control. This lets you set the gamepad up for any program, even ones that don't support gamepads. You can setup macros for each buttons and even control the mouse.
Long story short, if your after a gamepad and don't have one yet I recommend this one. ;)