If going by simply brand, Weruva. My cat is really picky but she'll eat both pates and their shreds. It's the only brand she eats shreds from. It's super expensive to feed as a sole diet though since there are usually low calorie, so it only makes a small portion of her diet currently. Their ingredients are usually pretty good, too.
I'd probably buy something much higher quality than what they are getting now. I'm not exactly sure what brands that would be but whatever is better than what they are currently getting.