Florida State
In my lifetime, I have seen it all regarding FSU football. I remember the 1970s teams that were awful. I remember the teams in the 1980s that were great. I have seen national title teams that have been elite. I have seen the decline late in the Bobby Bowden era where they were mediocre. I have seen the Jimbo Fisher years go from good to great to elite and now back to being just very good again.
The Seminoles went 14-0 and won the national title in 2013. In my opinion, this was one of the five best college football teams in my lifetime.