IMHO, Sony's Dual Analog/DualShock is about as good as gamepads come, which is probably why it's remained almost unchanged for 3 generations of consoles now. And even on the PC Logitech's Rumblepad is a carbon copy of it.
If I can give Microsoft one thing, they definitely rip off ideas with the best of them. The Xbox360 controller is by far the best I've ever used and it works with just about every Windows game I've tried in the past three years. It basically combines the old Nintendo controller style with the Dual Shock design but gives you wireless, removable batteries and great trigger buttons. The Dual Shock 3 triggers feel like mush, I have no idea why they went with em.