My brothers used to make me watch two that had to be the all time worst: the Banana Splits and The New Zoo Review (with Doug and Mary Jo, who was actually sort of hot in her go-go boots). The actors had to be doing drugs to get through an episode.
I think most of the other shows mentioned so far gave me a chuckle, but to this day I can't understand why, in F-Troop, Wilton Parmenter never got Wrangler Jane drunk and took her back to his bunk at Fort Courage. For that matter, if I was Uncle Joe, I wouldn't be movin' kinda slow at the junction if I knew those three hotties were taking a bath in the water tower.