Suppose you are a mathematics student who has just graduated and you haven't yet come to graduate school, or maybe you are in your first year of graduate school. Which magazines should you read? I mean general interest magazines, not journals of a specific field, but the kind of magazine that in each volume contain at least a couple of articles that every mathematician could understand (or reasonably try to understand) and be interested in. I don't even know how to describe exactly what I mean. That's why I am asking.

Please post one suggestion per answer.