Entertainment Weekly put together their "New EW 1000" (1000 best movies, tv shows, albums, etc).

Here are their top 10 "New TV Classics"

1. The Simpsons, Fox, 1989-present
2 The Sopranos, HBO (1999-2007)
3 Seinfeld, NBC (1989-98)
4 The X-Files, Fox (1993-2002)
5 Sex and the City, HBO (1998-2004)
6 Survivor, CBS (2000-present)
7 The Cosby Show, NBC (1984-92)
8 Lost, ABC (2004-present)
9 Friends, NBC (1994-2004)
10 Buffy the Vampire Slayer, The WB (1997-2001); UPN (2001-03)

Here is a link to their TV 100