Usually, as shows age, they resort to gimmicks to get people to watch. Finding season 3 a mixed bag, I was hesitant to purchase season 4. I did so because of the "Laugh-In" tie-in. But having started to watch, I found this opener to be rather funny.
Tony and Major Healy pilot a test ship. Jeannie blinks in and inadvertently sets the ship off course. It lands on a hillbilly farm.
While the hillbillies are parodies of the Beverly Hillbillies (oversexed male, late 20-something playing a 14 year old who's supposed to get a date, gun-totin' granny, and so on), I found a number of jokes to come out of left field. I would say the "bear hug" line leading to the funniest as, given the pacing, it's impossible to think of the corny punchline before it happens and the result is a hearty belly laugh.
Definitely worth watching for some good comic relief.