is there a legit software program to watch TV over the net on your PC?

Curious as i saw some ads that are scams on web pages. curious if there are any legit software programs you can watch tv shows, satellite programming and not just shows from foreign countries.., on your pc?

http://us.slingmedia.com/page/home

http://www.mobitv.com/

30 channels on your computer for $20/month.

Might want to look at http://www.joost.com/