What are the best offensive line situations in college football?

Oklahoma's Orlando Brown could be the top offensive lineman picked in next year's NFL draft. John David Mercer/USA TODAY Sports

Editor's note: This article was adapted from Phil Steele's college football preview magazine, which is available here.

Who has the best offensive lines in the country this season? There are some familiar names in the top 15, with Oklahoma, Alabama and Ohio State taking up the top three spots.