Most defenses in college football run some kind of a 4-2-5, with 4 on the LOS (most often 2 or 3 down, 1-2 up), 2 linebackers, 3 safeties and 2 corners.

Most split time in 4-3 or 4-2 depending on who they play and the flow of the game. And occasionally most play 3 man fronts as well, as much as that bothers some people. Jay Hill mentioned today that sometimes they would blitz and sometimes they would play cover. It all depends.