The two highlights I can recall from the 20+ years of commuting are a pair of bolt cutters and a basketball. Sort of funny thing about the basketball was I found on the way to work, left it in a rack used for holding large tanks, like those used for oxygen, liquid nitrogen, etc. and forgot about it for a month. Then I found it again recently and brought it home to my son, who was excited to have it. The last one we had got run over by a car and had not yet been replaced.