I found this site about a year ago. Watch Series Online for free, Full episodes - Watch Series The only catch is you have to click through a couple pages of ads to get to the show. But it's pretty darn good as long as you have good virus protection. You look up the show, click on the episode you want and it will give you a choice of sites it's avaiable on.
I only watch the shows I don't try to download them. They have almost all the seasons episodes of any shows I have ever looked up. If the show is current, the new episode is usually available the morning after it airs on TV. One thing though, make absolutely sure you are spelling the title correctly as it has no leaway regarding spelling.
Enjoy!