For Big Picture Mode, they always advertise on the game's Steam page that it supports full-controller or partial-controller. Next to that they show a picture of the Logitech F710. I know that they do support the Xbox 360 controller for Windows.
Are these the only controllers that Steam supports or are there more?
Officially, Steam Support states support for the following.
Currently, Big Picture supports the Xbox 360 Wireless Controller for Windows, the Xbox 360 Wired Controller, and the Logitech Wireless Gamepad F710.
In addition, you can infer support for a variety of third party gamepads that offer similar button layouts and drivers - for instance, any third party Xbox compatible gamepads should work just fine.
With the use of third party drivers like MotioninJoy, a variety of other options are usable as well, though unsupported.
