I understand there may have been some arguments about this subject, but for me, the best webpage is obviously Atari Compendium's list of VCS controllers. It goes on and on, telling the story of a million ideas, mostly bad, crapped out in a gold rush environment in a very short period of time. Boy does it go on. There are so many of them. Mercury-switched Le Stiks that kids held in their hands? Check! Combination joystick/paddles, almost none of them usable? Checkarooni! Shapes that no hand could ever really grasp? You got it! Something called the "Obelisk"? There is an obelisk. It goes on and on and on and on.
"Retrogaming" is, as we all know, a pretty stupid hobby, especially if real money gets exchanged in the process, but I might make an exception for weird old joysticks. I don't need them to plug into any authentic hardware - the 2600-daptor works fine for my purposes - but there's something tactile and pleasing about these old crapsticks. And unlike the mechanical keyboard thing, joystick hunting remains clunky and funky and resoundingly uncool and, therefore, largely cheap.
