Gravis www.gravis.com makes a Destroyer Gamepad that lists for about $9.99,
which is very similar to the basic SideWinder pad I've seen for $10-$12
around my area. They also have an Eliminator Aftershock that lists for $39
if you like Rumble Feedback.
The Sidewinders have the D-pad angled slightly towards center, and the
Gravis D-pads are angled straight ahead like Playstation Gamepads, so if
that's relevant to you, that's the difference. That's why I prefer the
Gravis, although I have a SideWinder I use too.