Hello,
While my official controller is still waiting for funds to complete it... I grabbed one of these:
http://us.thrustmaster.com/products/lookproduct.php3?productid=10&skin=Gamepads Thrustmaster Dual Power gamepad.
The thing is super sweet. Feels more comfortable than a PSX joypad... and I believe has more buttons. (2 on the underbelly - nice trigger like feel)
The analog can be switched to digital with a single button click - in the middle of a game! The analogs are very precise... and both work awesome with mame. (even works well for games like robotron, assault... sinistar, and Spyhunter! )
Theres even a keyboard emuation program so you can use the buttons for special functions. Tho - all the buttons are fully recognized in mame.
And finally, the dual power version has a rumble motor
Works cool for windows games that support it.
I just saw thier site... and it seems thay have a new model out, with dual motors. Looks sweet.
Anyway, I highly recomend them. They arnt to expensive... and they feel and perform incredible