Has an AFL game ever ended 121-28?
Exactly once. On July 11, 1925, Geelong beat Sydney 121-28, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 121-28 in league history.
That makes 121-28 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 122-28 has happened never and 121-29 has happened never.