The ones the Switch 'ear' controllers fit into are just shells to make them more comfortable to hold. I've not tried any of them I'm afraid! I decided early on that I didn't like the size and shape so I only use them on the Switch in handheld mode, I use the Pro controller otherwise.
If you've got two players with kid size hands, the 'ear' controllers are pretty great. Adult hands, not so much, even with the twin-ear holder that comes with the Switch for TV play.
The replacement for that bodge, the Pro controller is very much a 'normal' console controller and is excellent but £60.
One thing I did get recently was a left controller with a real D-pad instead of the four buttons, I've found it impossible to play games with the not-a-D-pad. This only works when plugged into the Switch, it's not a wireless controller, £22: www.amazon.co.uk/gp/product/B07FSWM4Z2?tag=mumsnetforum-21
Once I got over about 8 games downloaded (I don't use cartridges, I get all games from the e-shop) I needed a microSD card to increase the internal storage. I added a 64gig microSD for about a tenner (room for 10-20 more games). That's only important if you're using downloads not game cards though, game cards use nearly nothing, and it'll tell you when it's run out of space so don't buy early.
Other than the Pro, the d-pad, the microSD and a cheap case I've not needed any other bits'n'bobs.
Oh - SIL has kids the right age to enjoy the Labo cardboard builds, those things are amazing! The variety pack, kit one, is the place to start with those, each of the builds is most of a day so there's a lot of fun in that box.