Re: most "wrong" episode...
Jesus I just watched ENT's "Dear Doctor" for the first time since it premiered and it made me sick. I've always liked the Prime Directive but applied in places like this and in TNG's "Homebound" it's a nightmare.
I always found Dear Doctor offensive and incredibly short-sighted.
"...the most elementary and valuable statement in science, the beginning of wisdom, is I do not know." - Lt. Commander Data, "Where Silence Has Lease"