During last year I use Royal Canin. Puppies love the smell and taste of this dry kibbles. There are only one negatuve trait in this food. Kibbles made too small, and for fast eaters it can cause a chocking problem sometimes. But a great benefit of it - Royal Canin Chihuahua Puppy Dry Dog Food reduces stool odor with highly digestible proteins and precise fiber content. At the same time exceptional aromas and flavors to satisfy picky eaters.
Number #2 in my list is Merrick Lil'Plates. This food is good and smells ok too))
And optional - but not for every dog - I recommend Purina Pro Plan for Toy Breeds.
However this food is too dry and does not smell attractive. My puppies lost their interest to Purina very fast.
By the way one of the benefits of any dry food - the nutrition complex includes all nessesary vitamins and micro elements for growing puppies. And another trick - you can soak it in some water to convert into wet food, if your puppy prefer softer kibbles.