First let me say that I like the Trek, but there were a lot of cringe worthy moments in TOS and TNG not to mention a large amount of annoying characters.
For me the worst of the 1960s was summed up in TOS Season 3s "The Way to Eden".
Singing hippies on the Enterprise, luckily the most annoying die by the end of the episode.
There is a character called Adam who breaks into song at every opportunity. I would have loved to have seen a BSG moment, "Do that again and we'll throw you out of an airlock".
Truly terrible, little wonder TOS got cancelled shortly after this. The films were, IMHO, much better than the series.
Anyone else got any truly bad Trek moments to share/get off your chest?