You can't really go wrong when choosing nuts to eat

You can't really go wrong when choosing nuts to eat, as long as you pay attention to quality. By this I mean look for nuts that are organic and raw, not irradiated, pasteurized, or coated in sugar. One exception is peanuts, which are technically in the legume family. My main objections to peanuts are that they tend to:

Distort your omega-3 to omega-6 ratio, as they are relatively high in omega-6
Be frequently contaminated with a carcinogenic mold called aflatoxin
Be one of the most pesticide-contaminated crops.