Rick Sutcliffe: 1984
Rick Sutcliffe certainly had a respectable MLB career, and much of it was in a Cubs uniform. Although he won the National League Cy Young award in 1984, by all measures of the game, he probably should not have. New York Mets pitcher Dwight Gooden was the runner-up in the race, but he had better statistics than Sutcliffe in almost every major pitching category.
This is a real head-scratcher. Whether it was the fact that Gooden was a 19-year-old rookie or the fact that baseball writers used to put way too much value on wins and losses, the guy simply got snubbed by today's standards. That's not to take anything away from Sutcliffe, as he was a two-time All-Star for the Cubs and one of the team's main starting pitchers throughout the 80s. He is also a color broadcaster for the Cubs' Marquee Sports Network and regularly fills in for Jim Deshaies.