If you live outside US, you can pay for NFL Gamepass. You get all Preseason games and all regular season games + NFL Network. Of course, you have to pay extra for the playoffs and it is far from cheap. Best thing is that they archive the games during the season so you can go back and watch the games again and again if you choose to. This year they also provided the option of watching several games at the time. You can check it out here: http://gamepass.nfl.com There is a free demo, so you can check if your computer can handle it.
I have used it during the last 2 seasons, and it has simplified a lot for me. No more dodgy streams or waiting for the game to be released on the file sharing networks. It has had some problems with the load at the beginning of the season, but they have given me a refund for that and solved the problems to week 2.
A warning though, there is an auto renewal clause somewhere. You might want to opt out from that. I didn't last season (didn't see it) and they charged me with this season before I had decided to go with it.