1) Your Show of Shows
2) MASH (early years)
3) The Dick Van Dyke Show
There was never much competition for any other shows to fill these first three slots. Van Dyke & Company really did go out on top. The show's finale wasn't their best show, but they sure went into it with a bang because the two or three shows prior to it were either their best ever, or certainly among their best. But, like Jackie Gleason, they were smart enough to know when a show has run its course, and it truly had. Better to quit when you're ahead.