Best cookbook you own?

My personal favorite is [The Food Lab](The Food Lab: Better Home Cooking Through Science https://www.amazon.com/dp/0393081087/ref=cm_sw_r_cp_api_kFFLzbTY97D9X) since it shows the reasoning and science behind different techniques. What are some good cookbooks that you guys like, either just for recipes or for learning technique? I'm also wondering if anyone has any suggestions on a cookbook to get for my brother, who is planning on going to culinary school soon.