As video games have grown more complex and the technology better the controller has also consistently grown more complex. Bottom line - The more buttons means more progress of gaming.

A short overview* looks something like this:

Pong - ONE input. The beginning of consumer gaming had a potentiometer as the control input. Crude. Primitive.

Atari - TWO inputs. One button and one analog joystick. Better than one potentiometer but a severely limited control interface.

NES - FIVE inputs. D-Pad, A and B button, Select and Start. For most of the gameplay it added one button since the Select and Start were used infrequently in most games.

SNES - NINE inputs. D-Pad, A/B/X/Y, Left/Right Shoulder, Select and Start. Functionally more like seven inputs. A great leap in the the number of buttons and the path to more complex gameplay.

N64 - 12 inputs. D-Pad, A/B, Left/Right/Z, four C buttons, Start and the Analog Joystick. Nintendo did gamers a great favor by bringing back the Analog Joystick. Three more ways to push buttons pushed games from 2-D to 3-D.

PS2 - 15 inputs. D-Pad, X/[]/^/O, four shoulder buttons, Select, Start, two Analog Joysticks and Joysticks work as buttons. The addition of the second Analog Joystick was an evolutionary leap in adding more complexity to gameplay.

Wii - 10 inputs. D-Pad, A/B/Z/C/1/2/+/- and Analog Joystick. A step back.

PS3 & 360 - 15 inputs. Holding fast to last-gen standards.

PC - 101 inputs (keyboard) plus Mouse. The ultimate controller for numerical superiority in the realm of gaming complexity. Consoles have a lot of catching up to do.

Each generation the number of inputs has grown until this generation. As the number of inputs became greater the complexity of gameplay grew and (some say) games got better in part because of that. The uncontested leader in input prowess (and graphical prowess) is the PC. Because of that the PC has the most potential for complex gameplay input schemes.

Until consoles add more inputs they will not be able to match the PC in its sheer multitude of input choices. If consoles ever hope to catch up they must start adding more buttons, D-Pads or Joysticks... or maybe a mouse and a keyboard? Perhaps in the next generation we will see more complex input schemes created for the consoles. If consoles don't add more input options will they be forever doomed to a numerical disadvantage with the PC?

Bottom line: The more intelligently placed buttons means more progress for gaming.

*_{^{not comprehensive}}

Should motoin controls also count as inputs? Like lets say a function could be mapped to right left up down "waggle". Or what about 1:1 controls of Wii motion plus? I don't agree though that more inputs are necessary.

Atari 5200. 1982 (one year before Famicom). 13 inputs. Failed commercially.

wow, I disagree with fkusumot, it's madness

Wiimote
A
B
-
+
1
2
d pad
IR pointer
sixaxis technology
accelerometers (different to gyroscope technology)

edit: I forgot the home button

Nunchuk
c
z
analogue stick
sixaxis
accelerometers

Total = 16

And as for PC's superiority, I don't think that more inputs = better controls, with the exception of a few games

so many systems used a similar controller to that

Madness!

You stated that you didn't think more inputs = better controls, but hasn't that been the progression for the industry?

What were they thinking? Nintendo most revolutionary idea was the gamepad with the D-pad. Without it, we would have a weird looking phone as controller...

I think this kind of missed the point of control evolution. It's not the buttons, it's not the control sticks, it's the convenience factor.

PONG - Simple analog wheel. Linear precision control only. Pretty easy to use.

Atari - Various input methods, most notable being joystick + button. Still linear precision control only, and very stiff.

NES - D-pad input. Linear precision control, easy to use.

SNES - See: NES.

N64 - Analog input. Non-linear precision control, a bit too loose.

PS2 - See N64, but too stiff instead.

Wii - Analog, camera, and motion input. Non-linear precision control, but imprecise for motion input (MotionPlus should help with this).

PS3 & 360 - See PS2.

PC - Key-based input. Linear input only.

Now we have a remote.

the atari jaguar controller had way more buttons than all the consoles except pc, so all 3 had gone step back