The problem with the Keyboard Vs Controller question is simply that the PC has far too few games which it would make more sense to use a controller.
The second problem with PC controllers is like the PC itself, there is no standard - so if you say made a game with Playstation like controls with Force Feedback, then there are current only 3 controllers on the market (and they are bu no means cheap starting at £30 each) which have the buttons, FFB and 3D Sticks.
And most of these can't usually use the 3D Sticks and D-Pad at the same time!
At this place (as i'd forgotten before comming home) I have a selection of "adapted" console controllers, setup for either Gameport or USB which have drivers created by third parties.
Now for games like Tomb Raider, Rouge Squadron and alike then Controllers are awesome ... but for C&C or Quake3, etc... controllers are a curse!
Until there are more platformer and console style RPGs and Racers on the PC then there is no need.
As far as my Zelda clone is conserned, i will be setting that up with keyboard controls ... however i'll also be setting it up to specifically use the Gravis Aftershock Eliminator
Well just my veiws
Anata aru kowagaru no watashi!