The Razer Wolverine is by far the best controller I've ever purchased. Got it now... 7 years ago and it's still just an absolute champ. The initial price may scare off some, and the fact that it's wired, but it's the best damn controller I've ever used.

Flappers are 2 can be mapped to existing buttons (I have mine as up/down on the D-pad), and the other 2 raise/lower sensitivity of the sticks. So I can hold a flapper while sniping to get real precise.

It also has two little toggles on the inside between the bumpers which I have mapped to left/right on the dpad, which is really nice because I don't have to take my fingers off the sticks, Witcher 3 this is amazing because what's how you pull out a specific sword.

Cannot recommend more, Razer Wolverine.

Tons of third party controllers for any system clone existing buttons, which is nice when the official controllers don't have that. Something interesting about doing this on a switch is that because each joy con is its own independent controller you can only map each joy con to an input from the same joy con, for example, the left wouldn't be able to map to face buttons, and the right wouldn't be able to map to the d pad.

I use a Steam Controller on PC and really enjoy being able to map anything to it which helps being able to play games how I want. Cloning buttons is great for the whole "retain joystick movement while hitting a face button", but without being able to directly map different game controls to it it's just a copy of an existing function you already have.

I would love for grip buttons to be normalized and allow for more controls in games, it's pretty much the last part of my hands that aren't doing anything on a modern controller layout.

The GameSir T4k has them but I think they can only be mapped to existing buttons. I map them to left/right stick press.
Very nice affordable controller with hall effect analog sticks.

I have a SCUF Reflex FPS for the games that don’t need the adaptive trigger feature, and the regular one for the ones that do. They are expensive af, but I have joint hypermobility and the FPS version is the one that my hands hurt the least with, and it’s the one I most heavily use. The paddle shape and position fits my hand and it’s super lightweight.

SCUF has a reputation for poor quality control, but my FPS lived through the poorest treatment for a year, until the left trigger finally died. They don’t have a large warranty, but they repaired my controller without coverage for ~50€, and threw in a case (it’s included now, but wasn’t when I bought it) and thumbstick replacements when they sent it back.

I remember having a tough time choosing between the Wolverine v2 and the Victrix Gambit a while back when I needed a controller. I eventually went with the Gambit and I haven't regretted it. It has two swappable paddle pieces so you can choose between having either two paddles or four.