- Pretty much everything Apatow-related. No MSCL means no Freaks and Geeks.
- Friday Night Lights. The stark realism, honesty, and willingness to focus on outcasts are clearly children of MSCL. (Also, Veronica Mars, which is MSCL plus murder mystery, at least to an extent, and Felicity, which is MSCL goes to college.)
- Wicked. Book by MSCL creator Winnie Holzman.
- The careers of its cast, with Claire Danes becoming a (small) movie star, A.J. Langer and Tom Irwin continuing to work consistently in TV, and Jared Leto remaining famous for...um...being pretty.
- Subsequent Herskowitz/Zwick TV projects, including Once and Again and Relativity. (Among those who had big breaks on those shows? Lisa Edelstein, Richard Schiff, Poppy Montgomery, Adam Goldberg, and Evan Rachel Wood, and Patrick Dempsey's appearances on Once were part of how he become McDreamy.)
Celebrate the show. Knowing the demographic of this site and prior discussions, most of us have seen it. If you haven't, get thee to a local DVD emporium. If you have, you've probably already got plans to buy.