Bob of 1979. The other five are very destructive storms. Bob was a minor storm, but Bob is not remembered for what it did. Bob is remembered for being the first “himicane”. Prior to 1979 all storms had female names.
The years are important because a storm name is reused six years later, unless it was a particularly destructive storm. Thus, Bob of 1979 is also the only one on the list whose name was later reused (in 1985 and 1991).