Any good sci-fi tv shows like revolution, lost, falling skies, and walking dead?

[Quinn]

Also tell me how many season are there so far whether there are finish or still comming on

 

[Charlotte]

heroes. i watched the full series on lovefilm

 

[woodpecker]

Doctor Who is a science fiction classic. Still coming on air. The 50th anniversary is on November 23, 2013.