English Walnuts are great sources of thiamin, B6, folacin, potassium, phosphorus and magnesium, manganese and copper. Black walnuts are similar in nutrients, with some variations. Pistachio trees take more than a dozen years to begin producing, but then they produce for longer than one of our lifetimes. They've been grown in Turkey, Iran, Greece, and now California. Pistachios contain somewhat smaller amounts of some of the nutrients listed above, but don't forget that good nutrition doesn't come from just one food.
Cashew nuts are much like other nuts in nutrients, being extra high in copper and iron.
Brazil nuts have a pretty good supply of calcium and manganese, but are even better for thiamin, phosphorus, and copper. For best nutritional results, vary the kind of nuts you consume. Walnuts and almonds have more zinc than most others. Almonds, Brazil nuts, and cashews would be the stars for lecithin. Brazil nuts or pecans would be the best choices for B1.