"Thrustmaster Firestorm Dual Power Gamepad"
That's my fav for it. It's got for the most part the same layout as the original dual shock controllers.
Has the "R3" & "L3" buttons by pushing in the analog sticks (so you can play Ape Escape

)
A bit larger (good for my big hands).
A bit heavier.
Only one face button that you can use as "start".
Two additional buttons for your ring -or- middle fingers (depending on how you hold it. Sounds weird but they are lower than the top two shoulder buttons, and on their own "step", and it isn't uncomfortable). I use the left one for my select button.
And the d-pad IMO is better than Sony's Dual Shock Controller.
I personally prefer playing with this controller more than I do playing on my PSone or PS2 controllers. The analog sticks aren't as stiff, my hands don't feel so cramped together, & the grip on the gamepad is much better.