It really depends the game
Usually, I develop using a wired xbox 360 controller, but I'm just itching to program a game that uses my saitek x52 pro flight system.
It has more buttons and axis inputs than just about any device you'll find on pc, so it's great for edge cases. It even has an lcd display on it
Note that controller isn't xinput iirc but DirectInput instead.
There are some really esoteric controllers out there that use their own api. Hope to (insert deity of choice here) you never encounter one in the wild
This is exactly why I mention supporting both DInput and XInput. Yes, XBOX360/ONE are the de facto standard, but they aren't all that is out there. Everything else pretty much uses DInput still. Microsoft is from what I see the ONLY entity trying to get rid of DInput as all the manufacturers are still releasing devices for DInput support. And it also supports my reasoning behind custom input for the player. You just never know what they have, or what style of controls they like. The easiest way is to just support it all. I've never known a player that wants a really strange input scheme(like d-pad on the right for example), but that wasn't willing to set the controls up themselves in the options menu. You don't have to support directly all the possibly esoteric schemes if you just let them press the indicated button for the indicated action.