The best kind of chocolate chips for cookies are ones that have a minimum of 42% cacao. It doesn’t matter whether it’s bittersweet, milk, semi-sweet, white, or dark chocolate. Quality chocolate is crucial because you want a significant amount of cacao in your chips. If a chocolate chip has 60% cacao, the other 40% is sugar and emulsifiers. The least expensive chocolate chips will not mention a percentage for cacao because it’s the majority sugar. Even sugar-free chocolate chips highlight the cacao percentage because more chocolate equals less sugar or sugar alcohols. The evidence is in how well your chocolate chips melt after baking. Great chocolate chips will melt during baking, and even after the cookies have cooled off will still be melted. For this reason, I usually only use dark chocolate chips for baking cookies because the minimum cacao will be 63%. My favorite brands to use are Guittard and Ghirardelli. Inexpensive chocolate chips taste good and do the job, but you want to use quality ingredients when making something for people you love.