Miami was pretty much like Rutgers until Schnellenberger showed up in 1979-1980 and started building up for the 1983 national title. Their true "down period" in the 1990s was pretty much 1997, where they missed a bowl game for the first time in years and got blown out 47-0 by Florida State, but Butch Davis was able to recruit the nucleus of the 2000-2002 teams during that period(Dorsey, Shockey, Portis, McKinnie, etc.)
Notre Dame has had more down periods than people would like to believe, including the period between Frank Leahy and Ara Parseighan, the Gerry Faust years, and the Davie/Willingham era.
I'd say Michigan is a school that never seems to have a true down period. They may not win the Big Ten every year, but the last bad season they had was 1984 when they went .500, and then bounced back the next year anyway.