Has an AFL game ever ended 121-41?
Exactly once. On August 31, 2008, Richmond beat Melbourne 121-41, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 121-41 in league history.
That makes 121-41 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 122-41 has happened never and 121-42 has happened 1 times.