Apart from driving or flight simulations, which honestly I don't like to play one bit, most of the games offer either mouse&keyboard or Gamepad/Joystick controller settings.

A couple of months ago I bough a windows 360 controller for my PC.
I wanted to test Dead Island lauded analogue fighting controls, I wanted to fight as Batman without typing something wrong on the keyboard and playing Bastion like it's "supposed to be played".
There are other games, especially console ports which advertise their controller support. Steam has this grand scheme of "BIG PICTURE" where the whole Steam catalogue changes into some ugly form of xBOX/Playstation like control mess interface for your controller. Even Orcs Must Die! features controller support.

Now, as you were probably able to read between the lines, I suck at using a gamepad.
The cramps are just a minor issue nothing some good old pain killers and some exercise wouldn't get rid off, the problem is: I've just become a very bad player as soon as I take the gamepad in my hands.
The controls are not intuitive, there are to many buttons and functions in total. Some useless buttons are hidden away so that I always forget to use them. Like "Press & hold the left analogue stick to run" the vibration is just distracting me finding the right key to press so in other words it just breaks the immersion.

So I finally found out that I love my keyboard and mouse and would never give it up, additionally it taught me that I would never appreciate a console because it lacks mouse and keyboard control.

Now what interests me is:

Have you tried using a gamepad?
Are there any games that use a gamepad properly?
Are there any gamepads that work better for keyboard-freaks like me?

I do own a gamepad, and while I use my mouse & keyboard for most games, there are some that I find to work a lot better with a gamepad.
Vertically or horizontally scrolling shooters, be it Raiden, Touhou or Tyrian, I find these to be a lot easier to play with a gamepad.
Sidescrolling platformers, not including those where you aim independently of the direction that you are going (Abuse-style platformers).
Driving games (if you don't have a wheel). Analogue controls are far better than digital.

But apart from those, there are not many games that I would rather play with a gamepad than a mouse & keyboard.

Using the best tool for the right genre is key. La-Mulana is much more enjoyable with a gamepad, while DOOM is better with mouse and keyboard.

I'm in a similar situation as you. I bought an xbox 360 controller about a month ago, and while I don't think I suck with it, I have problems playing with it for more than an hour or so because it causes my fingers to ache. So I end up playing most games, even those designed for a controller, using the mouse and keyboard.

I play most side-scrollers with a gamepad, as well as the odd console port that insists on having fixed camera angles. There are side-scrollers built for mouse and keyboard (e.g. Abuse), but not very many.

Other than that, I almost always use mouse and keyboard. Even in Dark Souls.

You know what I really hate? Pressing the analogue sticks.

I do own one but apparently I'm gamepad dyslexic because every attempt at playing with one either quickly devolves into furious button mashing or results in very precise but completely wrong maneuvers.

Makes victories against friends all the more sweet, though...

I know I've posted this pic before and I really don't care. You can never post this pic enough.

This is the controller I use.

I like the idea of a controller and typically try it out on all the games that support it, but in the end speed and accuracy beat comfort and vibration. :D

I like using both KB/M and controller. Depends on the game, of course. Some games I prefer one over the other, and some games I like using both.

Been playing Red Faction: Guerrilla lately and it doesn't have proper support for switching between both KB/M and controller, but I prefer driving with the controller and shooting with the mouse. I've set up this weird combination of keybindings and Xpadder controls to make it work.

Most games nowadays support controller and keyboard, so it's usually not a problem for me. That is the worst. Especially if it's mapped to sprint. Press the stick down and move it? Nope. Never sprinting again.

I just got massively derepped for something and it wasn't that pic. XD I give up trying to figure this place out. :P

FYI I have more degrading sexist video game controller pics like that one so let me know if you are interested. :D I'm going to bed.

Sure, sexist videos are always welcome!!!

Hmm.. if you're not into driving or flying... Well I guess that rules GTA out too (which I always end up playing in a weird constantly switching between keyboard and controller style, for in or out of the car then get confused and find myself using a mad combination of both - gamepad stick pushed forward to run while aiming with mouse!)

Yeah, 2D and 3D platformers are my main thing to turn to gamepads for, outside of FlatOut and Crimson Skies - games like Cave Story+ and Soul Reaver

And I was waggling my Cruiser joystick on my C64 from a very early age, and the black rubber gimp joystick of the Atari 2600 before that thinking about it so mouse and keyboard is the newer thing for me so I'm struggling for advice but you could try a playstation rather than XBox style pad, that might click for you better, no idea why but PS fanboys swear by them and swear AT XBox ones for some reason!

Okay I am actually going to bed now but I wanted to throw out a little question regarding this topic and new technology specifically the 'eye guided' cursors or whatever you call them. Right now it all seems experimental but I'm guessing before long using yours hands when gaming may become retro and I was just curious what you folks thought about it. Personally the thought of using my own eyes to aim and move kind of scares the shit out of me but then I've always been a big pussy.

I am iffy about it, at best. It seems like motion controls, but with the eyes instead. I detest motion controls and don't like touch screens, so I am pretty biased against new control methods.

I'm looking forward to thought control.
The screen is never able to interpret the way I look. Let alone deduce where I want to go.