Here are the things I have (some multiples of):

Extra dock. I find it much easier to just have a 2nd dock in my living room.

Controller Charge dock. Mine is Mario themed, pretty sure it came from Gamestop. It likes me dock and charge my Pro Controller and my 2 joycons.

Pro Controller. I wasn't going to get one of these, then got a deal on one. Worth it, but a 3rd party one can be just as good.

Screen protector. I don't use my Switch in handheld very often. But I wasn't going to risk the screen.

Case. I have a slim case that wraps around the switch itself. It won't let me dock with it on, but I like... because...

Special dock. I have a special dock set up, it consist of THIS and THIS . Technically only the 2nd option is needed, but having a smaller dock on my desk was a major need back when I 1st got my switch. The extender lets me lay my switch down. Nothing to knock over, also I feel I can keep the vents better open to air flow.

Game case . I've had many different ones as I gain more games. This one is my go to one now.