Hmm, I'll have to go with A Matter of Honor.
Riker fucks some scientist's wife, he finds out and gets jealous, tries to kill him and blows up the station by accident.
You're thinking of an entirely different episode...
Anyway, off goes Contagion, it's the weakest of the lot.
It has Romulans, entering th neutral zone, a mysterious ancient culture and a Galaxy class ship blowing up, it should have been a far more coherent episode instead of a jumbled mess it turned out.
Not to mention the resolution of the episode is essentially "have you tried turning it off and on again?"...
The Schizoid Man
The Measure of a Man
Pen Pals
Q Who?
The Emissary
Peak Performance