ESPN recently published their offseason updates to college football Total QBR. After each season, they review actual game film to improve the data -- looking at things like yards through the air on a pass compared to yards after the catch.
While there were no major movers, Michigan State's Connor Cook jumped six spots into the top 10 due to the fact that 63% of his pass yards came through the air (rather than after the catch).
With very few reliable advanced metrics in college football, Total QBR is a great starting point. The biggest obstacle is the muddied and non-standardized play-by-play data across schools and the NCAA. Your top two quarterbacks in 2014? Marcus Mariota and J.T. Barrett.