I just thought about this while watching Encore Black today. It seems like most viewers/fans believe that the introduction of Maggie and in particular Sam was the jump the shark moment. I seems like having such a big event like a wedding (they even brought back the the original housekeeper, Mrs. Garrett for good measure) relatively late in the show's run (I think that Diff'rent Strokes lasted for two more seasons after this) feels awfully anti-climatic. I don't recall Diff'rent Strokes really having a proper series finale anyway (wasn't the last episode about roving reporter Arnold investigating athletes at his school using steroids).