If you live in the TV market of your favorite team, a digital antenna and amplifier is the most reliable/cheapest way to go. That's what I did 2-3 years ago. Only cost me like 30 bucks. A lot of people don't realize that the major networks switched from analog to digital over a decade ago. Now I get every Titans game in 1080p for free.
If you're out of market, I am not as dialed into that as I used to be. But I do know a buddy of mine who's a Cowboys fan has used NFLBites for the past couple of years. From what I recall from my illegal streaming days, there are plenty of options out there if you have an active VPN.