16. Ken Cosgrove
Showcase Episode: "Signal 30"
Ken's really a few different characters — he begins as a sexist jerk who mocks Peggy behind her back, but he turns into a surprising stand-up guy (as well as a loyal friend to the secretary-turned-ace-copywriter). He's also a science-fiction author who publishes his stories under secret pen names. Along the way, he manages to lose an eye in a hunting accident (was Dick Cheney working for Buick?) and marry the girl from The Secret World of Alex Mack. Seems like an even trade.