Buffy the Vampire Slayer (1997-2003)
Joss Whedon began his iconic TV career with this mash-up of teenage high-school soap opera and bad-ass horror monster movie — but, you know, classier. Adapted from the far cheesier (and Whedon-scripted) 1992 feature film, Buffy starred Sarah Michelle Gellar as the titular slayer, the show's literally-fighting-your-demons ethos made it a ripe and emotionally rich metaphor for high school and early adulthood. By the show's seventh and final season, it had more than one TV critic hailing it as the best scripted television series, ever.
The West Wing (1999-2006, though Sorkin left after the 2002-2003 season)
In its first four years on the air, The West Wing won four Best Drama Emmys, seven acting awards, two Humanitas prizes, two Peabody awards — and Sorkin wrote or co-wrote 85 of the 88 episodes.