TNG -- 'Lessons' - Always had a soft spot for this one.
'The Chase' - Must be in my bottom 25 of all Trek episodes. Worf accidentally destroys a Yridian command ship and absolutely nothing is done!! Really?? Galen is irritating and obnoxious, in fact the only good thing about this episode is the Klingon captain, who is very funny.
The Chase is fantastic...however, I believe it was implied the Yridians were destroyed for other reasons than the E-D firing on it...
Oh right... I must have missed that!! Was it the Romulans perhaps?