This is a list of tv shows that should be brought back because they ended too early or just because you want to see more.
http://www.ranker.com/list/tv-shows-that-should-be-brought-back-v2/slashlover,
As the World Turns
Buffy the Vampire Slayer
Charmed
Dexter
Hercules: The Legendary Journeys
Xena: Warrior Princess
Angel
Teen Titans
Breaking Bad
Merlin