Denny McLain won 31 games. Nobody has done that since then.
Hall of Famer Bob Gibson led the NL (and MLB) with a 1.12 ERA. According to this excellent profile by Roger Angell, Gibson was never taken out during an inning for the entire season.
Gibson pitched three World Series Game Sevens (1964, 1967, 1968) and won two. In 1968, he lost to Mickey Lolich of the Tigers. Lolich was overshadowed by McLain during the season but won three games in the World Series. Lolich was rather plump and ran a doughnut shop after he retired. You can’t make that up.