I use a webscraper to obtain data from ESPN's game pages, the NCAA's game pages, and Yahoo's recruiting site. I've been collecting and archiving data from various sources since 2011, and have managed to get a pretty comprehensive database going back to 2002 including an archive of all of the old cfbstats data.
It's free aside from the small amount of time I spend retooling the webscraper every time ESPN, NCAA, or Yahoo updates their site format. The data is not really in a good format for public consumption, however. I pull most of it down in JSON and store it that way. Since python can build native objects from JSON and serialize them back, I also work with it in that format, so it no longer enters a database or even a spreadsheet until I have a specific need to analyze it in a different format. That hasn't happened in a while.
If you're interested in free data, it means work. If you're interested in fast, timely, complete, well formatted data, you may end up having to pay for it. The last free reliable source I used was cfbstats, which has since become SportsSource analytics. They'll run you a couple hundred bucks per season for data. There was an open source python ESPN webscraper on github for a while that looked like it was working, but the last time I checked it was before ESPN updated their page format about a week before kickoff this year. No idea if it's still ticking. There are some football nerd types on some of the SBnation blogs that also appear to have some sort of advanced data source, but I have never bothered to research it. I'd be interested to know, though, if anybody else knows more about that.
We also have a couple of stats gurus on this site aside from myself who might know of something.