The devastating terrorist attacks of Sept. 11, 2001, were such a monumental moment in recent U.S. history that it's tempting sometimes to divide American popular culture into "pre-9/11" and "post-9/11." Tempting, yes — but not so easily done. Looking back, it's surprising just how many TV shows that we tend to identify with the '90s actually aired a sizable chunk of their episodes after the World Trade Center towers fell.