If you could design...

[The Warden]

I would make it somewhat like the Xbox 360's, with a see-through thin padding for extra comfort and prettiness, a little bit of reinforcing so it could stand you gripping it so hard it creaks with your anger, and A COMFORTABLE, WORKING FUCKING D-PAD.
I also might bring back the White and Black buttons from the original Xbox because that shit was much better.
Or with the power of fucking god, I'd create a machine that brings you into the game to simulate the experience, providing much better animation (Seeing as it's YOU) and a higher level of interaction.
Can you imagine playing games like Godfather with that shit?
IT'D BE FUCKING INCREDIBLE.
Also, if you attempted to tell characters of their deaths the system would slap you in the face. HARD. That'll teach ya bastards to try and break MY games.

 

[Mr.Governor]

similar to a ps2 one,ps3 ones sucks and xbox ones are big.

What?

The PS3 and PS2 controllers are almost the exact same thing. The PS3 just happens to have Sixaxis.

PS3s R2 and L2 controller buttons are too sensitive for me

 

[Kollega]

A Holodeck. If not Holodeck, then i could try the following set-up:

- A controller with the functionality of a Wiimote, on a front of which you can stick a block of plastic for balancing (i strongly doubt that moral guardians will let a controller resemble the pistol, but still). This controller is used to rotate camera, and has three buttons on it - one where the trigger is supposed to be, one on a left side behind the trigger, and one on the back near the top. Pretty ergonomic, i think.

- A glove, with which you can make different gestures to activate different abilities.

- For movement, some kind of pedals could be used. Say, left pedal is an analogue stick - you can tilt it to control movement. Right pedal is used for sprint and jump - not sure how exactly.

This set-up is not perfect, but at least it sounds intresting.

 

[Toastngravy]

We would go back to Joysticks.

All the controls you need right there.