There is no clear “best” when it comes to formula and depending on your local market, you may find both name and store brands that are very similar in content.
Formula is a product that is tightly regulated by the Food and Drug Administration to meet certain nutritional and safety standards.
While there are slight variations from company to company, all are safe for a typically developing infant. Some infants seem to prefer one over another, and some babies seem to spit up less after one verses another brand, but often they can be interchanged without trouble.
In general, formulas are divided into cow's milk-based and soy. Family preference is the biggest factor in choosing between these. If your baby has specific medical needs, your pediatrician will recommend which formula is right for them.