Undefeated seasons in 1897, 1907 and 1914.
The 2000 Dennis Erickson squad went 11-1 and plastered Notre Dame in the Fiesta Bowl, earned a share of the Pac-10 title. By far OSU's best season ever.
Other than that, the only other time the program was even mediocre was in the late 50's/60's under Tommy Prothro and Dee Andros. The Beavers finished below .500 every single year in the 70's, 80's and 90's. Thirty year losing streak.