The X-Files episode "Nothing Important Happened Today" airs 2001

The first episode of the ninth season of the X-Files, Nothing Important Happened Today, aired November 11, 2001.  I had lost touch with the series, but when I saw Lucy Lawless in the promos, I made a point to watch it.  David Duchovny was not in this episode, so Gillian Anderson (Agent Scully) was paired with Robert Patrick (Agent Doggett), as they investigate a beautiful woman (Lucy Lawless) who can breathe underwater.  

Cary Elwes also appears in this episode.  

"Xena: Warrior Princess" premieres 1995

Xena: Warrior Princess, a spin-off of Hercules: The Legendary Journeys, premiered on television September 4, 1995 and became a cult classic almost overnight.  It quickly eclipsed Hercules in the ratings and is still one of the biggest top culture shows ever.

It starred Lucy Lawless as the title character and Renee O'Connor as Gabrielle, the sidekick.  Joxer would show up later.

The premise of the series is Xena, a warlord (warlady?) or "Destroyer of Nations" has decided to change her ways and become good.  She teams up with Gabrielle as they travel the countryside standing up for the greater good.

The series ended in 2001.