Without reservation, I wholeheartedly recommend The Gourmet's Cookbook by Elek Magyar. I was given this book by a Hungarian friend who hoped I'd use it to cook some of his favourite dishes for him. This was the book his Mom used back in Hungary. These recipes deliver consistent, quality, authentic results.
Ive been cooking from the George Lang book for many years, very satisfied and its also a fine read..
Paul Kovi's Transylvanian cookbook is also very much worth a look.
I have Gourmet Pot by Kálmán Tolnai, which I bought sight unseen, because it seemed to be authoritative, and I wanted an authentic recipe for the paprika sauce used in goulash. I haven't used it for anything else. This book is so authentic and comprehensive that it contains a lot of unusual recipes that most Americans wouldn't want to make, even if they could.
About 500 recipes, several color illustrations. In English, but measurements are by weight and the terminology is sometimes obscure.