A few years ago I went around to a bunch of stores and played everything they had. I think, for the price, Cordoba has the best sound and feels the nicest. (out of the popular brands on the shelf) https://www.cordobaguitars.com/ukuleles/15cm/ I found this to be the bang for the buck.

Kalas sound a little tinny to my ears, but it's perhaps a more "classic" uke sound. The timbre is a little too shrill. Cordobas have a very mid-low punchy sound, and a "thunky" feel that carries MUCH longer. It feels lighter and resonates a lot more than a Kala. I haven't played a Donner and can't speak to them. Kala is very popular and easy to find, plus they also have tons of fun designs. I don't think you'll be disappointed with either.

I also have one of these: https://www.amazon.com/gp/product/B07QKTYHCP that I picked up on sale. This will definitely not be as loud as a full body uke, but I got it to play to my son before bed, and it's great for that. It's much easier to hold and comfortable. It's also a ridiculously nice build quality for the money. Hricane may not be a popular brand, but I've been very happy with it. The spruce top will be sweeter/sharper than the mahogany of the Cordoba.

If you want to drop a low g string on it at some point, I would lean towards the Cordoba because it will have that deeper sound profile.